BioLargo (BLGO) 10-Q 17 May 23 2023 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2023	May 15, 2023
Document Information [Line Items]
Entity Central Index Key	0000880242
Entity Registrant Name	BIOLARGO, INC.
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2023
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2023
Document Transition Report	false
Entity File Number	000-19709
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	65-0159115
Entity Address, Address Line One	14921 Chestnut St.
Entity Address, City or Town	Westminster
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92683
City Area Code	888
Local Phone Number	400-2863
Title of 12(b) Security	Common stock
Trading Symbol	BLGO
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		284,690,284

Consolidated Balance Sheets (Cu

Consolidated Balance Sheets (Current Period Unaudited) - USD ($)	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 3,264,000	$ 1,851,000
Accounts receivable, net of allowance	1,380,000	1,064,000
Inventories, net of allowance	135,000	120,000
Prepaid expenses and other current assets	95,000	118,000
Total current assets	4,874,000	3,153,000
Equipment, net of depreciation	391,000	287,000
Other non-current assets	124,000	124,000
Investment in South Korean joint venture	27,000	33,000
Right of use, operating lease, net of amortization	837,000	867,000
Clyra Medical prepaid marketing	394,000	394,000
Total assets	6,647,000	4,858,000
Current liabilities:
Accounts payable and accrued expenses	1,224,000	940,000
Debt obligations	66,000	100,000
Deferred revenue	21,000	17,000
Lease liability	97,000	97,000
Deposits	113,000	184,000
Total current liabilities	1,799,000	1,576,000
Long-term liabilities:
Debt obligations, net of current	302,000	237,000
Lease liability, net of current	747,000	773,000
Total long-term liabilities	1,296,000	1,271,000
Total liabilities	3,095,000	2,847,000
COMMITMENTS AND CONTINGENCIES (Note 12)
STOCKHOLDERS’ EQUITY:
Preferred Series A, $0.00067 Par Value, 50,000,000 Shares Authorized, -0- Shares Issued and Outstanding, at March 31, 2023 and December 31, 2022	0	0
Common stock, $0.00067 Par Value, 550,000,000 Shares Authorized, 284,122,581 and 278,462,706 Shares Issued, at March 31, 2023 and December 31, 2022, respectively	190,000	186,000
Additional paid-in capital	150,191,000	148,435,000
Accumulated deficit	(143,841,000)	(143,594,000)
Accumulated other comprehensive loss	(155,000)	(149,000)
Total BioLargo Inc. and subsidiaries stockholders’ equity	6,385,000	4,878,000
Non-controlling interest	(2,833,000)	(2,867,000)
Total stockholders’ equity	3,552,000	2,011,000
Total liabilities and stockholders’ equity	6,647,000	4,858,000
Entities, Excluding Partially Owned Subsidiary [Member]
Current liabilities:
Accounts payable and accrued expenses	1,224,000	940,000
Partially Owned Subsidiary [Member]
Current liabilities:
Accounts payable and accrued expenses	278,000	238,000
Long-term liabilities:
Debt obligations, net of current	$ 247,000	$ 261,000

Consolidated Balance Sheets (_2

Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - $ / shares	Mar. 31, 2023	Dec. 31, 2022
Convertible Preferred Stock, Par Value (in dollars per share)	$ 0.00067	$ 0.00067
Convertible Preferred Stock, Shares Authorized (in shares)	50,000,000	50,000,000
Convertible Preferred Stock, Shares Issued (in shares)	0	0
Convertible Preferred Stock, Shares Outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.00067	$ 0.00067
Common stock, shares authorized (in shares)	550,000,000	550,000,000
Common stock, shares issued (in shares)	284,122,581	278,462,706

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Revenue from Contract with Customer, Including Assessed Tax	$ 3,742,000	$ 965,000
Cost of revenue
Cost of Goods and Services Sold	(1,932,000)	(444,000)
Gross profit	1,810,000	521,000
Operating expenses:
Selling, general and administrative expenses	1,722,000	1,839,000
Research and development	565,000	392,000
Total operating expenses	2,287,000	2,231,000
Operating loss	(477,000)	(1,710,000)
Other income (expense):
PPP forgiveness	0	174,000
Grant income	31,000	5,000
Interest expense	(48,000)	(13,000)
Total other (expense) income	(17,000)	166,000
Net loss	(494,000)	(1,544,000)
Net (loss) income attributable to noncontrolling interest	(247,000)	108,000
Net loss attributable to common stockholders	$ (247,000)	$ (1,652,000)
Net loss per share attributable to common stockholders:
Loss per share attributable to stockholders – basic and diluted (in dollars per share)	$ (0.0009)	$ (0.0063)
Weighted average number of common shares outstanding: (in shares)	280,711,278	260,805,418
Comprehensive loss attributable to common stockholders
Net loss	$ (494,000)	$ (1,544,000)
Foreign currency translation adjustment	(6,000)	(8,000)
Comprehensive loss	(500,000)	(1,552,000)
Comprehensive (loss) income attributable to noncontrolling interest	(247,000)	108,000
Comprehensive loss attributable to stockholders	(253,000)	(1,660,000)
Product [Member]
Revenue from Contract with Customer, Including Assessed Tax	3,548,000	610,000
Cost of revenue
Cost of Goods and Services Sold	(1,797,000)	(293,000)
Service [Member]
Revenue from Contract with Customer, Including Assessed Tax	194,000	355,000
Cost of revenue
Cost of Goods and Services Sold	$ (135,000)	$ (151,000)

Consolidated Statement of Stock

Consolidated Statement of Stockholders' Equity (Deficit) (Unaudited) - USD ($)	Clyra Medical Technologies [Member] Common Stock [Member]	Clyra Medical Technologies [Member] Additional Paid-in Capital [Member]	Clyra Medical Technologies [Member] Retained Earnings [Member]	Clyra Medical Technologies [Member] AOCI Attributable to Parent [Member]	Clyra Medical Technologies [Member] Noncontrolling Interest [Member]	Clyra Medical Technologies [Member]	BioLargo Energy Technologies, Inc (BETI) [Member] Common Stock [Member]	BioLargo Energy Technologies, Inc (BETI) [Member] Additional Paid-in Capital [Member]	BioLargo Energy Technologies, Inc (BETI) [Member] Retained Earnings [Member]	BioLargo Energy Technologies, Inc (BETI) [Member] AOCI Attributable to Parent [Member]	BioLargo Energy Technologies, Inc (BETI) [Member] Noncontrolling Interest [Member]	BioLargo Energy Technologies, Inc (BETI) [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Noncontrolling Interest [Member]	Total
Balance (in shares) at Dec. 31, 2021													255,893,726
Balance at Dec. 31, 2021													$ 171,000	$ 143,718,000	$ (139,121,000)	$ (115,000)	$ (3,720,000)	$ 933,000
Sale of stock for cash (in shares)													6,703,789
Sale of stock for cash													$ 4,000	1,198,000	0	0	0	1,202,000
Issuance of common stock for services (in shares)													86,752
Issuance of common stock for services													$ 0	17,000	0	0	0	17,000
Stock option compensation expense	$ 0	$ 141,000	$ 0	$ 0	$ 0	$ 141,000							0	660,000	0	0	0	660,000
Noncontrolling interest allocation													0	(528,000)	0	0	528,000	0
Net loss													0	0	(1,652,000)	0	108,000	(1,544,000)
Foreign currency translation													$ 0	0	0	(8,000)	0	(8,000)
Balance (in shares) at Mar. 31, 2022													262,684,267
Balance at Mar. 31, 2022													$ 176,000	145,205,000	(140,773,000)	(123,000)	(3,085,000)	1,400,000
Balance (in shares) at Dec. 31, 2022													278,462,706
Balance at Dec. 31, 2022													$ 186,000	148,435,000	(143,594,000)	(149,000)	(2,867,000)	2,011,000
Sale of stock for cash (in shares)													4,201,402
Sale of stock for cash													$ 3,000	797,000	0	0	0	800,000
Issuance of common stock for services (in shares)													930,490
Issuance of common stock for services													$ 1,000	206,000	0	0	0	207,000
Issuance of common stock in exchange for Clyra shares (in shares)													527,983
Stock option compensation expense													$ 0	195,000	0	0	0	195,000
Clyra Medical Technologies, Inc. (Clyra) stock options issued for services	0	61,000	0	0	0	61,000
Warrant issued for interest													0	30,000	0	0	0	30,000
Clyra – sales of Series A Preferred Stock	0	0	0	0	225,000	225,000	$ 0	$ 0	$ 0	$ 0	$ 550,000	$ 550,000
Clyra – Series A Preferred Stock – dividend	$ 0	$ 0	$ 0	$ 0	$ (27,000)	$ (27,000)
Noncontrolling interest allocation													0	467,000	0	0	(467,000)	0
Net loss													0	0	(247,000)	0	(247,000)	(494,000)
Foreign currency translation													$ 0	0	0	(6,000)	0	(6,000)
Balance (in shares) at Mar. 31, 2023													284,122,581
Balance at Mar. 31, 2023													$ 190,000	$ 150,191,000	$ (143,841,000)	$ (155,000)	$ (2,833,000)	$ 3,552,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash flows from operating activities
Net loss	$ (494,000)	$ (1,544,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock option compensation expense	256,000	801,000
Common stock issued for services	207,000	17,000
Interest expense related to amortization of the discount on note payable	3,000	4,000
Fair value of warrant issued for interest	30,000	0
PPP loan forgiveness	0	(174,000)
Loss on investment in South Korean joint venture	6,000	8,000
Depreciation expense	22,000	2,000
Changes in assets and liabilities:
Accounts receivable	(316,000)	(178,000)
Inventories	(17,000)	(29,000)
Prepaid expenses and other assets	25,000	(59,000)
Deferred revenue	4,000	(89,000)
Right of use and lease liability, net	4,000	0
Deposit	(71,000)	12,000
Net cash used in operating activities	(43,000)	(1,140,000)
Cash flows from investing activities
Equipment purchases	(48,000)	(32,000)
Net cash used in investing activities	(48,000)	(32,000)
Cash flows from financing activities
Proceeds from sale of common stock	800,000	1,202,000
Repayment of note payable	(50,000)	0
Repayment by Clyra on inventory line of credit	(15,000)	(10,000)
Proceeds from sale of Clyra Medical preferred stock	225,000	0
Net cash provided by financing activities	1,510,000	1,192,000
Net effect of foreign currency translation	(6,000)	(8,000)
Net change in cash	1,413,000	12,000
Cash at beginning of year	1,851,000	962,000
Cash at end of period	3,264,000	974,000
Supplemental disclosures of cash flow information
Interest	15,000	7,000
Income taxes	5,000	0
Short-term lease payments not included in lease liability	13,000	52,000
Non-cash investing and financing activities
Equipment added via vehicle loan	80,000	0
Allocation of noncontrolling interest	467,000	528,000
Conversion of Clyra Common Stock to BioLargo Common Stock [Member]
Non-cash investing and financing activities
Conversion of Clyra common stock to BioLargo common stock	100,000	0
Conversion of Intercompany Receivable into Clyra Shares [Member]
Non-cash investing and financing activities
Conversion of intercompany receivable into Clyra shares	0	633,000
BETI Common Stock [Member]
Cash flows from financing activities
Proceeds from sale of common stock	550,000	0
Entities, Excluding Partially Owned Subsidiary [Member]
Changes in assets and liabilities:
Accounts payable and accrued expenses	284,000	114,000
Accounts payable and accrued expenses	284,000	114,000
Partially Owned Subsidiary [Member]
Changes in assets and liabilities:
Accounts payable and accrued expenses	14,000	(25,000)
Accounts payable and accrued expenses	$ 14,000	$ (25,000)

Note 1 - Business and Organizat

Note 1 - Business and Organization	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	Note 1. Description of Business BioLargo, Inc. (“BioLargo”, or the “Company”) invents, develops, and commercializes innovative platform technologies to solve challenging environmental problems like PFAS contamination (per- and polyfluoroalkyl substances), advanced water and wastewater treatment, industrial odor control, air quality control, infection control, and myriad environmental remediation challenges. Our business strategy is straightforward: we invent or acquire technologies that we believe have the potential to be disruptive in large commercial markets; we develop and validate these technologies to advance and promote their commercial success as we leverage our considerable scientific, engineering, and entrepreneurial talent; we then monetize these technical assets through a variety of business structures that may Organization We are a Delaware corporation formed in 1991. 2006; 2009; 2022; 2014; 2016. 9 2017, 2012, 2022. 2, 8 Liquidity / Going concern The accompanying consolidated financial statements have been prepared on a going concern basis, which contemplates the realization of assets and the settlement of liabilities and commitments in the normal course of our business. For the three March 31, 2023, 11 March 31, 2023, During the three March 31, 2023, 3 3 6 8 10 As of March 31, 2023, 4 4 2024 8 Subsequent to March 31, 2023, 13 If we are unable to rely on our current arrangement with Lincoln Park to fund our working capital requirements, we will have to rely on other forms of financing, and there is no The foregoing factors raise substantial doubt about our ability to continue as a going concern, unless we are able to continue to raise funds through stock sales to Lincoln Park or other private financings, and in the long term, our ability to attain a reasonable threshold of operating efficiencies and achieve profitable operations by licensing or otherwise commercializing products incorporating our technologies. The consolidated financial statements do not

Note 2 - Summary of Significant

Note 2 - Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Significant Accounting Policies [Text Block]	Note 2. Principles of Consolidation The consolidated financial statements include the accounts of the Company, its wholly owned subsidiaries, and partially owned subsidiaries BETI, BLEST and Clyra Medical. All intercompany accounts and transactions have been eliminated. Foreign Currency The Company has designated the functional currency of BioLargo Water, Inc., our Canadian subsidiary, to be the Canadian dollar. Therefore, translation gains and losses resulting from differences in exchange rates are recorded in accumulated other comprehensive income. Cash and Cash Equivalents The Company considers all highly liquid investments with maturities of three one $250,000 not As of March 31, 2023, December 31, 2022, March 31, 2023 December 31, BioLargo, Inc. and subsidiaries $ 3,171 $ 1,685 Clyra Medical Technologies, Inc. 93 166 Total $ 3,264 $ 1,851 Accounts Receivable Trade accounts receivable are recorded net of allowances for doubtful accounts. Estimates for allowances for doubtful accounts are determined based on payment history and individual customer circumstances. The allowance for doubtful accounts as of March 31, 2023, December 31, 2022 Credit Concentration We have a limited number of customers that account for significant portions of our revenue. During the three March 31, 2023, three March 31, 2022, March 31, 2023 March 31, Customer A 86 % 29 % Customer B <10 % 14 % At March 31, 2023, December 31, 2022, March 31, 2023 December 31, 2022 Customer A 70 % 24 % Inventory Inventories are stated at the lower of cost or net realizable value using the average cost method. The allowance for obsolete inventory as of March 31, 2023, December 31, 2022, March 31, 2023 December 31, Raw material $ 52 $ 46 Finished goods 83 74 Total $ 135 $ 120 Other Non-Current Assets Other non-current assets consisted of (i) security deposits related to our business offices, (ii) three October 22, 2021, March 31, 2023 December 31, 2022 Patents $ 34 $ 34 Security deposits 36 36 Tax credit receivable 54 54 Total $ 124 $ 124 Equity Method of Accounting On March 20, 2020, We account for our investment in the joint venture under the equity method of accounting. We have determined that while we have significant influence over the joint venture through our technology license and our position on the Board of Directors, we do not three March 31, 2023, 2022, Impairment Long-lived and definite lived intangible assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not Earnings (Loss) Per Share We report basic and diluted earnings (loss) per share (“EPS”) for common and common share equivalents. Basic EPS is computed by dividing reported earnings by the weighted average shares outstanding. Diluted EPS is computed by adding to the weighted average shares the dilutive effect if convertible notes payable, stock options and warrants were exercised into common stock. For the three March 31, 2023, 2022, Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and revenues and expenses during the period reported. Actual results could differ from those estimates. Estimates are used when accounting for stock-based transactions, debt transactions, derivative liabilities, allowance for bad debt, asset depreciation and amortization, impairment expense, among others. The methods, estimates and judgments we use in applying these most critical accounting policies have a significant impact on the results of our financial statements. Share-Based Compensation Expense We recognize compensation expense for stock option awards on a straight-line basis over the applicable service period of the award, which is the vesting period. Fair value is determined on the grant date. Share-based compensation expense is based on the grant date fair value estimated using the Black-Scholes Option Pricing Model. For stock and stock options issued to consultants and other non-employees for services, the Company measures and records an expense as of the earlier of the date at which either: a commitment for performance by the non-employee has been reached or the non-employee’s performance is complete. The equity instruments are measured at the current fair value, and for stock options, the instruments are measured at fair value using the Black Scholes option model. The following methodology and assumptions were used to calculate share-based compensation for the three March 31, 2023, 2022: 2023 2022 Non Plan 2018 Plan Non Plan 2018 Plan Risk free interest rate 3.48 % 3.48 % 2.32 – 3.83% 2.32 – 3.83% Expected volatility 114 % 114 % 114 – 117% 114 – 117% Expected dividend yield — — — — Forfeiture rate — — — — Life in years 10 10 10 10 Expected price volatility is the measure by which our stock price is expected to fluctuate during the expected term of an option. The expected volatility is derived from the historical daily change in the market price of our common stock, as we believe that historical volatility is the best indicator of future volatility. The risk-free interest rate used in the Black-Scholes calculation is based on the prevailing U.S. Treasury yield as determined by the U.S. Federal Reserve. We have never paid any cash dividends on our common stock and do not Warrants Warrants issued with our convertible and non-convertible debt instruments are accounted for under the fair value and relative fair value method. The warrant is first not. not If the warrant is determined to not Convertible debt instruments are recorded at fair value, limited to a relative fair value based upon the percentage of its fair value to the total fair value including the fair value of the warrant. The warrant relative fair values are also recorded as a discount to the convertible promissory notes. As present, these equity features of the convertible promissory notes have recorded a discount to the convertible notes that is substantially equal to the proceeds received. Non-Cash Transactions We determine the value assigned to each intangible we acquire, and/or services or products received for non-cash consideration of our common stock based on the market price of our common stock issued as consideration, at the date of the agreement of each transaction or when the service is rendered or product is received. Revenue Recognition We account for revenue in accordance with ASC 606, Step 1: Step 2: Step 3: Step 4: Step 5: The Company’s products are sold through a contract with the customer and a written purchase order, in which the details of the contract are defined including the transaction price and method of shipment. The only performance obligation is to create and ship the product, and each product has separate pricing. Revenue is recognized at a point in time when the goods are shipped if the agreement is FOB manufacturer, and when goods are delivered if FOB destination. Revenue is recognized with a reduction for sales discounts, as appropriate and negotiated in the customer’s purchase order. Service contracts are performed through a written contract, which specifies the performance obligations and the rate at which the services will be billed, typically by time and materials. Each service is separately negotiated and priced. Revenue is recognized as services are performed and completed, or, for services related to product installations, at the completion of the installation. A few contracts have called for milestone or fixed cost payments, where we invoice an agreed-to amount per month for the life of the contract. In these instances, completed work, billed hourly, is recognized as revenue. If the billing amount is greater or lesser than the completed work, a receivable or payable is created. These accounts are adjusted upon additional billings as the work is completed. To date, there have been no The Company has outstanding contract liability obligations of $21,000 as of March 31, 2023, three March 31 ,2023. As we generate revenues from royalties or license fees from our intellectual property, a licensee will pay a license fee in one third Clyra also has certain distribution agreements that call for consigned inventory. Although the product is shipped to a third not Government Grants We have been awarded multiple research grants from the private and public Canadian research programs. The income we receive directly from grants is recorded as other income. We have been awarded over 80 first 2015. third third six eighteen not The grants typically provide for (i) recurring monthly amounts, (ii) reimbursement of costs for research talent for which we invoice to request payment, and (iii) ancillary cost reimbursement for research talent travel related costs. All awarded grants have specific requirements on how the money is spent, typically to employ researchers. None may Not no Income Taxes The asset and liability approach is used to recognize deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the carrying amounts and the tax bases of asset and liabilities. Deferred tax assets and liabilities are determined based on the differences between financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. The effect on deferred tax asset and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. We account for uncertainties in income tax law under a comprehensive model for the financial statement recognition, measurement, presentation, and disclosure of uncertain tax positions taken or expected to be taken in income tax returns as prescribed by generally accepted accounting principles (“GAAP”). Under GAAP, the tax effects of a position are recognized only if it is “more-likely-than- not” not not” no March 31, 2023, December 31, 2022. The Company assessed its earnings history, trends and estimates of future earnings and determined that the deferred tax asset could not March 31, 2023, December 31, 2022. The Company recognizes interest and penalties on income taxes as a component of income tax expense, should such an expense be realized. Fair Value of Financial Instruments Management believes the carrying amounts of the Company’s financial instruments as of March 31, 2023 December 31, 2022 Tax Credits Our research and development activities in Canada may not Leases At inception of a lease contract, we assess whether the contract is, or contains, a lease. Our assessment is based on: ( 1 2 3 not no March 31, 2023, nine not not 12 not As of March 31, 2023, Equipment Equipment is stated at cost less accumulated depreciation. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, which range from 3 - 5 years. Additions, renewals, and betterments that significantly extend the life of the asset are capitalized. Expenditures for repairs and maintenance are charged to expense as incurred. For assets sold or otherwise disposed of, the cost and related accumulated depreciation and amortization are removed from the accounts, and any related gain or loss is reflected in income for the period. Measurement of Credit Losses on Financial Instruments In June 2016, 2016 13, January 1, 2023 Accounts receivable are customer obligations that are unconditional. Accounts receivable are presented net of an allowance for doubtful accounts for expected credit losses, which represents an estimate of amounts that may not no not March 31, 2023 December 31, 2022, Recent Accounting Pronouncements Currently there are no

Note 3 - Sale of Stock for Cash

Note 3 - Sale of Stock for Cash	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Stock Purchase Agreement [Text Block]	Note 3. Lincoln Park Financing On December 13, 2022, “2022 three may three 12 no first 2022 1 December 23, 2022. January 19, 2023. During the three March 31, 2023, 2022, Unit Offerings During the three March 31, 2023, 2022, six five 6,

Note 4 - Debt Obligations

Note 4 - Debt Obligations	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Debt Disclosure [Text Block]	Note 4. The following table summarizes our debt obligations outstanding as of March 31, 2023, December 31, 2022 ( not 8, March 31, 2023 December 31, Current portion of debt: SBA Paycheck Protection Program loan $ 43 $ 43 Vehicle loan, current portion 13 — Convertible note payable, matures March 1, 2023 — 50 SBA EIDL Loan, matures July 2053, current portion 10 10 Debt discount, net of amortization — (3 ) Total current portion of debt $ 66 $ 100 Long-term debt: SBA Paycheck Protection Program loans, matures May 2025 $ 97 $ 97 Vehicle loan, matures March 2029 65 — SBA EIDL Loan, matures July 2053 140 140 Total long-term debt, net of current $ 302 $ 237 Total $ 368 $ 337 For the three March 31, 2023, 2022, Vehicle loan On February 7, 2023, March 7, 2029. Convertible note payable, matures March 1, 2023 On March 6, 2023, 10 five 6 SBA Program Loans On February 7, 2022, May 12, 2022, May 2025. In July 2020, three March 31, 2023,

Note 5 - Share-based Compensati

Note 5 - Share-based Compensation	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Compensation and Employee Benefit Plans [Text Block]	Note 5. Issuance of Common Stock in exchange for Services Payment of Officer Salaries On March 31, 2023, 12 Payment of Consultant Fees On March 31, 2023, On March 31, 2022, All of these offerings and sales were made in reliance on the exemption from registration contained in Section 4 2 not Stock Option Expense During the three March 31, 2023, 2022, 2018 8 2018 On June 22, 2018, 2018 “2018 may June 22, 2028. 2018 2018 January 1 st March 31, 2023, Activity for our stock options under the 2018 three March 31, 2023, 2022, Options Exercise Weighted share Aggregate (1) Balance, December 31, 2022 28,484,549 $0.12 – 0.43 $ 0.19 Granted 1,320,498 $0.20 $ 0.2 Balance, March 31, 2023 29,805,047 $0.12 – 0.43 $ 0.19 Unvested (4,073,761 ) $0.12 – 0.32 $ 0.19 Vested, March 31, 2023 25,731,286 $0.12 – 0.43 $ 0.19 $ 678,000 Balance, December 31, 2021 23,186,142 $0.16 – 0.40 $ 0.19 Granted 2,621,229 $0.12 – 0.23 $ 0.23 Balance, March 31, 2022 25,807,371 $0.12 – 0.40 $ 0.19 ( 1 March 31, 2023. The options granted to purchase 1,320,498 shares during the three March 31, 2023 with an aggregate fair value of $248,000 $65,000; four The options granted to purchase 2,621,229 shares during the three March 31, 2022 with an aggregate fair value of $564,000 $9,000; $96,000; four Chief Financial Officer Contract Extension On March 21, 2023, February 1, 2008 ( March 21, 2023 ( one January 31, 2024 ( As the sole compensation for the Extended Term, Mr. Dargan was issued an option (“Option”) to purchase 25,000 shares of the Company’s common stock for each month during the Extended Term (thus, an option to purchase 300,000 shares reflecting an extended term of 12 March 21, 2023, March 31, 2023, March 21, 2023 ten 2018 The Option is Mr. Dargan’s sole compensation for the Extended Term. As was the case in all prior terms of his engagement, there is no no not 2007 On September 7, 2007, April 29, 2011, 2007 “2007 may September 7, 2017. September 2017, Activity for our stock options under the 2007 three March 31, 2023, 2022 Weighted Average Aggregate Options Exercise Price per intrinsic Outstanding price per share share Value (1) Balance, December 31, 2022 1,904,085 $0.28 – 0.69 $ 0.56 Expired – – – Balance, March 31, 2023 1,904,085 $0.28 – 0.69 $ 0.56 $ – Balance, December 31, 2021 2,879,246 $0.23 – 0.94 $ 0.49 Expired – – – Balance, March 31, 2022 2,879,246 $0.23 – 0.94 $ 0.49 ( 1 March 31, 2023. Non-Plan Options issued Activity of our non-plan stock options issued for the three March 31, 2023 2022 Weighted Non-plan average Aggregate Options Exercise price per intrinsic outstanding price per share share value (1) Balance, December 31, 2022 19,023,829 $0.12 – 0.83 $ 0.39 Granted 48,804 0.20 0.20 Balance, March 31, 2023 19,072,633 $0.12 – 0.83 $ 0.39 Unvested (507,500 ) 0.45 0.45 Vested, March 31, 2023 18,565,133 $0.12 – 0.83 $ 0.38 $ 88,000 Balance, December 31, 2021 20,119,207 $0.12 – 0.83 $ 0.39 Granted 32,609 0.23 0.23 Balance, March 31, 2022 20,151,816 $0.12 – 0.83 $ 0.39 ( 1 March 31, 2023. During the three March 31, 2023, During the three March 31, 2022,

Note 6 - Warrants

Note 6 - Warrants	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Warrants [Text Block]	Note 6. We have certain warrants outstanding to purchase our common stock, at various prices, as described in the following table: Weighted average Aggregate Warrants Exercise price per intrinsic outstanding price per share share value (1) Balance, December 31, 2022 49,023,398 $0.13 – 1.00 $ 0.26 Granted 7,512,000 0.21 – 0.29 0.25 Expired (4,684,986 ) 0.19 – 0.35 0.21 Balance, March 31, 2023 51,850,412 $0.13 – 1.00 $ 0.26 $ 122,000 Balance, December 31, 2021 36,765,562 $0.16 – 1.00 $ 0.27 Granted 10,393,936 0.20 – 0.25 0.22 Expired (388,889 ) 0.22 0.22 Balance, March 31, 2022 46,770,549 $0.14 – 1.00 $ 0.29 ( 1 March 31, 2023. Warrants issued in Unit Offerings During the three March 31, 2023, 3 six five During the three March 31, 2022, 2020 3 six five Warrant issued in conjunction with amendment to note payable On March 6, 2023, 4, March 1, 2023”) five Fair Value – Interest Expense To determine interest expense related to our outstanding warrants issued in conjunction with debt offerings, the fair value of each award grant is estimated on the date of grant using the Black-Scholes option pricing model and the relative fair values are amortized over the life of the warrant. For the determination of expense of warrants issued for services, extinguishment of debt and settlement management also uses the option-pricing model. The principal assumptions we used in applying this model were as follows: 2023 2022 Risk free interest rate 3.88 – 4.27% 3.69 – 3.88% Expected volatility 40 – 95% 40% Expected dividend yield — — Forfeiture rate — — Expected life in years 3 – 5 3 The risk-free interest rate is based on U.S. Treasury yields in effect at the time of grant. Expected volatilities are based on historical volatility of our common stock. The expected life in years is based on the contract term of the warrant.

Note 7 - Accounts Payable and A

Note 7 - Accounts Payable and Accrued Expenses	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Accounts Payable and Accrued Liabilities Disclosure [Text Block]	Note 7. As of March 31, 2023, Category BioLargo ONM BLEST Water Intercompany Totals Accounts payable $ 169 $ 794 $ 37 $ 121 $ (82 ) $ 1,039 Accrued payroll 36 49 75 — — 160 Accrued interest 25 — — — — 25 Total $ 1,224 As of December 31, 2022, Category BioLargo ONM BLEST Water Intercompany Totals Accounts payable $ 187 $ 486 $ 7 $ 119 $ (82 ) $ 717 Accrued payroll 20 58 120 — — 198 Accrued interest 25 — — — — 25 Total $ 940 See Note 8,

Note 8 - Noncontrolling Interes

Note 8 - Noncontrolling Interest - Clyra Medical	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Noncontrolling Interest Disclosure [Text Block]	Note 8. Clyra Medical As discussed in Note 2 March 31, 2023. Debt Obligations of Clyra Medical Promissory Note On April 8, 2022, April 8, 2024, may Line of Credit On June 30, 2020, one one first 6 may On December 13, 2022, September 30, 2024, As of March 31, 2023, December 31, 2022, $161,000. Equity Transactions As of December 31, 2022, March 31, 2023, Sales of Common Stock During the three March 31, 2023, not March 2, 2022, Sales of Series A Preferred Stock During the three March 31, 2023, December 20, 2022, two no one may Each investor also entered into an agreement with BioLargo whereby the investor may 20% 30 18 18 not June 30, 2023, Clyra Stock Options Weighted Clyra average Options Exercise price per Outstanding price per share share Balance, December 31, 2022 15,833 $1.00 - 310 $ 5.53 Granted 426 1.00 - 271 148.27 Balance, March 31, 2023 16,259 $1.00 - 310 $ 9.27 Balance, December 31, 2021 14,004 $ 1.00 $ 1.00 Granted 648 1.00 1.00 Balance, March 31, 2022 14,652 $ 1.00 $ 1.00 Clyra issues options to its employees and consultants in lieu of compensation owed on a regular basis. The fair value of the options issued in the three March 31, 2023, 2022 no March 31, 2023 December 31, 2022 Risk free interest rate 3.88 – 4.27% 2.32 % Expected volatility 40% 40 % Expected dividend yield — — Forfeiture rate — — Expected life in years 10 10 Accounts Payable and Accrued Expenses At March 31, 2023, December 31, 2022, Category 2023 2022 Accounts payable $ 235 $ 186 Accrued payroll 6 45 Accrued interest 8 7 Accrued dividend 29 --- Total $ 278 $ 238 The accrued dividend relates to the Series A Preferred Stock. Clyra is not may

Note 9 - BioLargo Engineering,

Note 9 - BioLargo Engineering, Science and Technologies, LLC	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Wholly-Owned Subsidiary [Text Block]	Note 9. In September 2017, six 11 two no five five March 31, 2018 ( not first not September 2018. The BLEST Compensation Committee has met regularly since the subsidiary commenced operations. In 2018, not not November 2019, one one not January 2021, one one one December 31, 2020. January 2022, one one December 31, 2021. December 2022, one one $135,000 December 31, 2022. At March 31, 2023,

Note 10 - BioLargo Energy Techn

Note 10 - BioLargo Energy Technologies, Inc.	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Noncontrolling Interest Disclosure [Text Block]	Note 8. Clyra Medical As discussed in Note 2 March 31, 2023. Debt Obligations of Clyra Medical Promissory Note On April 8, 2022, April 8, 2024, may Line of Credit On June 30, 2020, one one first 6 may On December 13, 2022, September 30, 2024, As of March 31, 2023, December 31, 2022, $161,000. Equity Transactions As of December 31, 2022, March 31, 2023, Sales of Common Stock During the three March 31, 2023, not March 2, 2022, Sales of Series A Preferred Stock During the three March 31, 2023, December 20, 2022, two no one may Each investor also entered into an agreement with BioLargo whereby the investor may 20% 30 18 18 not June 30, 2023, Clyra Stock Options Weighted Clyra average Options Exercise price per Outstanding price per share share Balance, December 31, 2022 15,833 $1.00 - 310 $ 5.53 Granted 426 1.00 - 271 148.27 Balance, March 31, 2023 16,259 $1.00 - 310 $ 9.27 Balance, December 31, 2021 14,004 $ 1.00 $ 1.00 Granted 648 1.00 1.00 Balance, March 31, 2022 14,652 $ 1.00 $ 1.00 Clyra issues options to its employees and consultants in lieu of compensation owed on a regular basis. The fair value of the options issued in the three March 31, 2023, 2022 no March 31, 2023 December 31, 2022 Risk free interest rate 3.88 – 4.27% 2.32 % Expected volatility 40% 40 % Expected dividend yield — — Forfeiture rate — — Expected life in years 10 10 Accounts Payable and Accrued Expenses At March 31, 2023, December 31, 2022, Category 2023 2022 Accounts payable $ 235 $ 186 Accrued payroll 6 45 Accrued interest 8 7 Accrued dividend 29 --- Total $ 278 $ 238 The accrued dividend relates to the Series A Preferred Stock. Clyra is not may
BioLargo Energy Technologies, Inc (BETI) [Member]
Notes to Financial Statements
Noncontrolling Interest Disclosure [Text Block]	Note 10. Subsidiary BioLargo Energy Technologies, Inc. (“BETI”) was formed for the purpose of commercializing a sodium-sulfur battery technology. During the three March 31, 2023, six one third Each investor also entered into an agreement with BioLargo whereby the investor may 20 2024. As of March 31, 2023,

Note 11 - Business Segment Info

Note 11 - Business Segment Information	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Segment Reporting Disclosure [Text Block]	Note 11. BioLargo currently has four four 1. ONM Environmental -- which sells odor and volatile organic control products and services (located in Westminster, California); 2. Clyra Medical Technologies (“Clyra Medical”) -- which develops and sells medical products based on our technologies; 3. BLEST -- which provides professional engineering services on a time and materials basis for outside clients and supports our internal operations as needed (located in Oak Ridge, Tennessee); and 4. BioLargo Water (“Water”) -- which historically focused entirely on R&D, and has now shifted its focus to commercializing the AOS technology (located in Edmonton, Alberta Canada). 5. BioLargo Energy Technologies, Inc. (“BETI”) – formed to commercialize a sodium-sulfur battery technology. Other than ONM Environmental during the last three none third The segment information for the three March 31, 2023, 2022, March 31, 2023 BioLargo ONM Clyra BLEST Water BETI Elimination Total Revenue $ — $ 3,543 $ 6 $ 363 $ — $ — $ (170 ) $ 3,742 Intersegment revenue — — — (170 ) — — 170 — R&D expense (189 ) — (134 ) (245 ) (135 ) (32 ) 170 (565 ) Operating income (loss) (799 ) 1,387 (426 ) (368 ) (184 ) (87 ) — (477 ) Grant income — — — — 31 — — 31 Interest expense (36 ) (2 ) (10 ) — — — — (48 ) Net income (loss) (835 ) 1,385 (436 ) (368 ) (153 ) (87 ) — (494 ) March 31, 2022 BioLargo ONM Clyra BLEST Water Elimination Total Revenue $ 2 $ 600 $ 10 $ 545 $ — $ (188 ) $ 965 Intersegment revenue (2 ) (2 ) — (188 ) — 192 — Research and development (265 ) — (16 ) (108 ) (197 ) 194 (392 ) Operating loss (1,220 ) 13 (240 ) (35 ) (228 ) — (1,710 ) Grant income — — — — 5 — 5 Interest expense (6 ) — (7 ) — — — (13 ) Net income (loss) (1,226 ) 187 (247 ) (35 ) (223 ) — (1,544 ) As of March 31, 2023 BioLargo ONM Clyra BLEST Water BETI Elimination Total Tangible assets $ 530 $ 3,392 $ 578 $ 505 $ 223 $ 628 $ (73 ) $ 5,783 Right of use (leased assets) 114 — — 723 — — 837 Investment in South Korean joint venture 27 — — — — — 27 Total $ 671 $ 3,392 $ 578 $ 1,228 $ 223 $ 628 $ (73 ) $ 6,647 As of December 31, 2022 BioLargo ONM Clyra BLEST Water Elimination Total Tangible assets $ 669 $ 2,064 $ 631 $ 441 $ 194 $ (41 ) $ 3,958 Right of use (leased assets) 136 — — 731 — — 867 Investment in South Korean joint venture 33 — — — — — 33 Total $ 838 $ 2,064 $ 631 $ 1,172 $ 194 $ (41 ) $ 4,858

Note 12 - Commitments and Conti

Note 12 - Commitments and Contingencies	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Commitments and Contingencies Disclosure [Text Block]	Note 12. Office Leases We have long-term operating leases for office, industrial and laboratory space in Westminster, California, Oak Ridge, Tennessee, and Alberta, Canada. Payments made under operating leases are charged to the Consolidated Statement of Operations and Comprehensive Loss on a straight-line basis over the term of the operating lease agreement. Short-term leases less than one not three March 31, 2023, 2022, August 2024. not four four not September 2022, ten one None no not no

Note 13 - Subsequent Events

Note 13 - Subsequent Events	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Subsequent Events [Text Block]	Note 13. Management has evaluated subsequent events through the date of the filing of this quarterly report and management noted the following for disclosure. Lincoln Park Capital Purchase of Shares From April 1, 2023, May 12, 2023, 2022 3 1 333 268973 Clyra Medical – Series A Preferred From April 1, 2023, May 12, 2023, 3 may 20% 30 8,

Significant Accounting Policies

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Consolidation, Policy [Policy Text Block]	Principles of Consolidation The consolidated financial statements include the accounts of the Company, its wholly owned subsidiaries, and partially owned subsidiaries BETI, BLEST and Clyra Medical. All intercompany accounts and transactions have been eliminated.
Foreign Currency Transactions and Translations Policy [Policy Text Block]	Foreign Currency The Company has designated the functional currency of BioLargo Water, Inc., our Canadian subsidiary, to be the Canadian dollar. Therefore, translation gains and losses resulting from differences in exchange rates are recorded in accumulated other comprehensive income.
Cash and Cash Equivalents, Policy [Policy Text Block]	Cash and Cash Equivalents The Company considers all highly liquid investments with maturities of three one $250,000 not As of March 31, 2023, December 31, 2022, March 31, 2023 December 31, BioLargo, Inc. and subsidiaries $ 3,171 $ 1,685 Clyra Medical Technologies, Inc. 93 166 Total $ 3,264 $ 1,851
Receivable [Policy Text Block]	Accounts Receivable Trade accounts receivable are recorded net of allowances for doubtful accounts. Estimates for allowances for doubtful accounts are determined based on payment history and individual customer circumstances. The allowance for doubtful accounts as of March 31, 2023, December 31, 2022
Concentration Risk, Credit Risk, Policy [Policy Text Block]	Credit Concentration We have a limited number of customers that account for significant portions of our revenue. During the three March 31, 2023, three March 31, 2022, March 31, 2023 March 31, Customer A 86 % 29 % Customer B <10 % 14 % At March 31, 2023, December 31, 2022, March 31, 2023 December 31, 2022 Customer A 70 % 24 %
Inventory, Policy [Policy Text Block]	Inventory Inventories are stated at the lower of cost or net realizable value using the average cost method. The allowance for obsolete inventory as of March 31, 2023, December 31, 2022, March 31, 2023 December 31, Raw material $ 52 $ 46 Finished goods 83 74 Total $ 135 $ 120
Other Assets, Policy [Policy Text Block]	Other Non-Current Assets Other non-current assets consisted of (i) security deposits related to our business offices, (ii) three October 22, 2021, March 31, 2023 December 31, 2022 Patents $ 34 $ 34 Security deposits 36 36 Tax credit receivable 54 54 Total $ 124 $ 124
Equity Method Investments [Policy Text Block]	Equity Method of Accounting On March 20, 2020, We account for our investment in the joint venture under the equity method of accounting. We have determined that while we have significant influence over the joint venture through our technology license and our position on the Board of Directors, we do not three March 31, 2023, 2022,
Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block]	Impairment Long-lived and definite lived intangible assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not
Earnings Per Share, Policy [Policy Text Block]	Earnings (Loss) Per Share We report basic and diluted earnings (loss) per share (“EPS”) for common and common share equivalents. Basic EPS is computed by dividing reported earnings by the weighted average shares outstanding. Diluted EPS is computed by adding to the weighted average shares the dilutive effect if convertible notes payable, stock options and warrants were exercised into common stock. For the three March 31, 2023, 2022,
Use of Estimates, Policy [Policy Text Block]	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and revenues and expenses during the period reported. Actual results could differ from those estimates. Estimates are used when accounting for stock-based transactions, debt transactions, derivative liabilities, allowance for bad debt, asset depreciation and amortization, impairment expense, among others. The methods, estimates and judgments we use in applying these most critical accounting policies have a significant impact on the results of our financial statements.
Share-Based Payment Arrangement [Policy Text Block]	Share-Based Compensation Expense We recognize compensation expense for stock option awards on a straight-line basis over the applicable service period of the award, which is the vesting period. Fair value is determined on the grant date. Share-based compensation expense is based on the grant date fair value estimated using the Black-Scholes Option Pricing Model. For stock and stock options issued to consultants and other non-employees for services, the Company measures and records an expense as of the earlier of the date at which either: a commitment for performance by the non-employee has been reached or the non-employee’s performance is complete. The equity instruments are measured at the current fair value, and for stock options, the instruments are measured at fair value using the Black Scholes option model. The following methodology and assumptions were used to calculate share-based compensation for the three March 31, 2023, 2022: 2023 2022 Non Plan 2018 Plan Non Plan 2018 Plan Risk free interest rate 3.48 % 3.48 % 2.32 – 3.83% 2.32 – 3.83% Expected volatility 114 % 114 % 114 – 117% 114 – 117% Expected dividend yield — — — — Forfeiture rate — — — — Life in years 10 10 10 10 Expected price volatility is the measure by which our stock price is expected to fluctuate during the expected term of an option. The expected volatility is derived from the historical daily change in the market price of our common stock, as we believe that historical volatility is the best indicator of future volatility. The risk-free interest rate used in the Black-Scholes calculation is based on the prevailing U.S. Treasury yield as determined by the U.S. Federal Reserve. We have never paid any cash dividends on our common stock and do not
Warrant Policy [Policy Text Block]	Warrants Warrants issued with our convertible and non-convertible debt instruments are accounted for under the fair value and relative fair value method. The warrant is first not. not If the warrant is determined to not Convertible debt instruments are recorded at fair value, limited to a relative fair value based upon the percentage of its fair value to the total fair value including the fair value of the warrant. The warrant relative fair values are also recorded as a discount to the convertible promissory notes. As present, these equity features of the convertible promissory notes have recorded a discount to the convertible notes that is substantially equal to the proceeds received.
Non Cash Transactions [Policy Text Block]	Non-Cash Transactions We determine the value assigned to each intangible we acquire, and/or services or products received for non-cash consideration of our common stock based on the market price of our common stock issued as consideration, at the date of the agreement of each transaction or when the service is rendered or product is received.
Revenue from Contract with Customer [Policy Text Block]	Revenue Recognition We account for revenue in accordance with ASC 606, Step 1: Step 2: Step 3: Step 4: Step 5: The Company’s products are sold through a contract with the customer and a written purchase order, in which the details of the contract are defined including the transaction price and method of shipment. The only performance obligation is to create and ship the product, and each product has separate pricing. Revenue is recognized at a point in time when the goods are shipped if the agreement is FOB manufacturer, and when goods are delivered if FOB destination. Revenue is recognized with a reduction for sales discounts, as appropriate and negotiated in the customer’s purchase order. Service contracts are performed through a written contract, which specifies the performance obligations and the rate at which the services will be billed, typically by time and materials. Each service is separately negotiated and priced. Revenue is recognized as services are performed and completed, or, for services related to product installations, at the completion of the installation. A few contracts have called for milestone or fixed cost payments, where we invoice an agreed-to amount per month for the life of the contract. In these instances, completed work, billed hourly, is recognized as revenue. If the billing amount is greater or lesser than the completed work, a receivable or payable is created. These accounts are adjusted upon additional billings as the work is completed. To date, there have been no The Company has outstanding contract liability obligations of $21,000 as of March 31, 2023, three March 31 ,2023. As we generate revenues from royalties or license fees from our intellectual property, a licensee will pay a license fee in one third Clyra also has certain distribution agreements that call for consigned inventory. Although the product is shipped to a third not
Government Grants [Policy Text Block]	Government Grants We have been awarded multiple research grants from the private and public Canadian research programs. The income we receive directly from grants is recorded as other income. We have been awarded over 80 first 2015. third third six eighteen not The grants typically provide for (i) recurring monthly amounts, (ii) reimbursement of costs for research talent for which we invoice to request payment, and (iii) ancillary cost reimbursement for research talent travel related costs. All awarded grants have specific requirements on how the money is spent, typically to employ researchers. None may Not no
Income Tax, Policy [Policy Text Block]	Income Taxes The asset and liability approach is used to recognize deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the carrying amounts and the tax bases of asset and liabilities. Deferred tax assets and liabilities are determined based on the differences between financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. The effect on deferred tax asset and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. We account for uncertainties in income tax law under a comprehensive model for the financial statement recognition, measurement, presentation, and disclosure of uncertain tax positions taken or expected to be taken in income tax returns as prescribed by generally accepted accounting principles (“GAAP”). Under GAAP, the tax effects of a position are recognized only if it is “more-likely-than- not” not not” no March 31, 2023, December 31, 2022. The Company assessed its earnings history, trends and estimates of future earnings and determined that the deferred tax asset could not March 31, 2023, December 31, 2022. The Company recognizes interest and penalties on income taxes as a component of income tax expense, should such an expense be realized.
Fair Value of Financial Instruments, Policy [Policy Text Block]	Fair Value of Financial Instruments Management believes the carrying amounts of the Company’s financial instruments as of March 31, 2023 December 31, 2022
Tax Credits [Policy Text Block]	Tax Credits Our research and development activities in Canada may not
Lessee, Leases [Policy Text Block]	Leases At inception of a lease contract, we assess whether the contract is, or contains, a lease. Our assessment is based on: ( 1 2 3 not no March 31, 2023, nine not not 12 not As of March 31, 2023,
Property, Plant and Equipment, Policy [Policy Text Block]	Equipment Equipment is stated at cost less accumulated depreciation. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, which range from 3 - 5 years. Additions, renewals, and betterments that significantly extend the life of the asset are capitalized. Expenditures for repairs and maintenance are charged to expense as incurred. For assets sold or otherwise disposed of, the cost and related accumulated depreciation and amortization are removed from the accounts, and any related gain or loss is reflected in income for the period.
Credit Loss, Financial Instrument [Policy Text Block]	Measurement of Credit Losses on Financial Instruments In June 2016, 2016 13, January 1, 2023 Accounts receivable are customer obligations that are unconditional. Accounts receivable are presented net of an allowance for doubtful accounts for expected credit losses, which represents an estimate of amounts that may not no not March 31, 2023 December 31, 2022,
New Accounting Pronouncements, Policy [Policy Text Block]	Recent Accounting Pronouncements Currently there are no

Note 2 - Summary of Significa_2

Note 2 - Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2023
Notes Tables
Schedule of Cash and Cash Equivalents [Table Text Block]	March 31, 2023 December 31, BioLargo, Inc. and subsidiaries $ 3,171 $ 1,685 Clyra Medical Technologies, Inc. 93 166 Total $ 3,264 $ 1,851
Schedules of Concentration of Risk, by Risk Factor [Table Text Block]	March 31, 2023 March 31, Customer A 86 % 29 % Customer B <10 % 14 % March 31, 2023 December 31, 2022 Customer A 70 % 24 %
Schedule of Inventory, Current [Table Text Block]	March 31, 2023 December 31, Raw material $ 52 $ 46 Finished goods 83 74 Total $ 135 $ 120
Schedule of Other Assets, Noncurrent [Table Text Block]	March 31, 2023 December 31, 2022 Patents $ 34 $ 34 Security deposits 36 36 Tax credit receivable 54 54 Total $ 124 $ 124
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	2023 2022 Non Plan 2018 Plan Non Plan 2018 Plan Risk free interest rate 3.48 % 3.48 % 2.32 – 3.83% 2.32 – 3.83% Expected volatility 114 % 114 % 114 – 117% 114 – 117% Expected dividend yield — — — — Forfeiture rate — — — — Life in years 10 10 10 10

Note 4 - Debt Obligations (Tabl

Note 4 - Debt Obligations (Tables)	3 Months Ended
	Mar. 31, 2023
Notes Tables
Schedule of Debt [Table Text Block]	March 31, 2023 December 31, Current portion of debt: SBA Paycheck Protection Program loan $ 43 $ 43 Vehicle loan, current portion 13 — Convertible note payable, matures March 1, 2023 — 50 SBA EIDL Loan, matures July 2053, current portion 10 10 Debt discount, net of amortization — (3 ) Total current portion of debt $ 66 $ 100 Long-term debt: SBA Paycheck Protection Program loans, matures May 2025 $ 97 $ 97 Vehicle loan, matures March 2029 65 — SBA EIDL Loan, matures July 2053 140 140 Total long-term debt, net of current $ 302 $ 237 Total $ 368 $ 337

Note 5 - Share-based Compensa_2

Note 5 - Share-based Compensation (Tables)	3 Months Ended
	Mar. 31, 2023
Notes Tables
Share-Based Payment Arrangement, Option, Activity [Table Text Block]	Options Exercise Weighted share Aggregate (1) Balance, December 31, 2022 28,484,549 $0.12 – 0.43 $ 0.19 Granted 1,320,498 $0.20 $ 0.2 Balance, March 31, 2023 29,805,047 $0.12 – 0.43 $ 0.19 Unvested (4,073,761 ) $0.12 – 0.32 $ 0.19 Vested, March 31, 2023 25,731,286 $0.12 – 0.43 $ 0.19 $ 678,000 Balance, December 31, 2021 23,186,142 $0.16 – 0.40 $ 0.19 Granted 2,621,229 $0.12 – 0.23 $ 0.23 Balance, March 31, 2022 25,807,371 $0.12 – 0.40 $ 0.19 Weighted Average Aggregate Options Exercise Price per intrinsic Outstanding price per share share Value (1) Balance, December 31, 2022 1,904,085 $0.28 – 0.69 $ 0.56 Expired – – – Balance, March 31, 2023 1,904,085 $0.28 – 0.69 $ 0.56 $ – Balance, December 31, 2021 2,879,246 $0.23 – 0.94 $ 0.49 Expired – – – Balance, March 31, 2022 2,879,246 $0.23 – 0.94 $ 0.49 Weighted Non-plan average Aggregate Options Exercise price per intrinsic outstanding price per share share value (1) Balance, December 31, 2022 19,023,829 $0.12 – 0.83 $ 0.39 Granted 48,804 0.20 0.20 Balance, March 31, 2023 19,072,633 $0.12 – 0.83 $ 0.39 Unvested (507,500 ) 0.45 0.45 Vested, March 31, 2023 18,565,133 $0.12 – 0.83 $ 0.38 $ 88,000 Balance, December 31, 2021 20,119,207 $0.12 – 0.83 $ 0.39 Granted 32,609 0.23 0.23 Balance, March 31, 2022 20,151,816 $0.12 – 0.83 $ 0.39

Note 6 - Warrants (Tables)

Note 6 - Warrants (Tables)	3 Months Ended
	Mar. 31, 2023
Notes Tables
Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block]	Weighted average Aggregate Warrants Exercise price per intrinsic outstanding price per share share value (1) Balance, December 31, 2022 49,023,398 $0.13 – 1.00 $ 0.26 Granted 7,512,000 0.21 – 0.29 0.25 Expired (4,684,986 ) 0.19 – 0.35 0.21 Balance, March 31, 2023 51,850,412 $0.13 – 1.00 $ 0.26 $ 122,000 Balance, December 31, 2021 36,765,562 $0.16 – 1.00 $ 0.27 Granted 10,393,936 0.20 – 0.25 0.22 Expired (388,889 ) 0.22 0.22 Balance, March 31, 2022 46,770,549 $0.14 – 1.00 $ 0.29
Schedule Of Assumptions Used To Determine Fair Value Of Warrants [Table Text Block]	2023 2022 Risk free interest rate 3.88 – 4.27% 3.69 – 3.88% Expected volatility 40 – 95% 40% Expected dividend yield — — Forfeiture rate — — Expected life in years 3 – 5 3

Note 7 - Accounts Payable and_2

Note 7 - Accounts Payable and Accrued Expenses (Tables)	3 Months Ended
	Mar. 31, 2023
Notes Tables
Schedule of Accounts Payable and Accrued Liabilities [Table Text Block]	Category BioLargo ONM BLEST Water Intercompany Totals Accounts payable $ 169 $ 794 $ 37 $ 121 $ (82 ) $ 1,039 Accrued payroll 36 49 75 — — 160 Accrued interest 25 — — — — 25 Total $ 1,224 Category BioLargo ONM BLEST Water Intercompany Totals Accounts payable $ 187 $ 486 $ 7 $ 119 $ (82 ) $ 717 Accrued payroll 20 58 120 — — 198 Accrued interest 25 — — — — 25 Total $ 940

Note 8 - Noncontrolling Inter_2

Note 8 - Noncontrolling Interest - Clyra Medical (Tables)	3 Months Ended
	Mar. 31, 2023
Notes Tables
Schedule of Other Ownership Interests [Table Text Block]	Weighted Clyra average Options Exercise price per Outstanding price per share share Balance, December 31, 2022 15,833 $1.00 - 310 $ 5.53 Granted 426 1.00 - 271 148.27 Balance, March 31, 2023 16,259 $1.00 - 310 $ 9.27 Balance, December 31, 2021 14,004 $ 1.00 $ 1.00 Granted 648 1.00 1.00 Balance, March 31, 2022 14,652 $ 1.00 $ 1.00
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	2023 2022 Non Plan 2018 Plan Non Plan 2018 Plan Risk free interest rate 3.48 % 3.48 % 2.32 – 3.83% 2.32 – 3.83% Expected volatility 114 % 114 % 114 – 117% 114 – 117% Expected dividend yield — — — — Forfeiture rate — — — — Life in years 10 10 10 10
Schedule of Accounts Payable and Accrued Liabilities [Table Text Block]	Category BioLargo ONM BLEST Water Intercompany Totals Accounts payable $ 169 $ 794 $ 37 $ 121 $ (82 ) $ 1,039 Accrued payroll 36 49 75 — — 160 Accrued interest 25 — — — — 25 Total $ 1,224 Category BioLargo ONM BLEST Water Intercompany Totals Accounts payable $ 187 $ 486 $ 7 $ 119 $ (82 ) $ 717 Accrued payroll 20 58 120 — — 198 Accrued interest 25 — — — — 25 Total $ 940
Clyra Medical [Member]
Notes Tables
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	March 31, 2023 December 31, 2022 Risk free interest rate 3.88 – 4.27% 2.32 % Expected volatility 40% 40 % Expected dividend yield — — Forfeiture rate — — Expected life in years 10 10
Schedule of Accounts Payable and Accrued Liabilities [Table Text Block]	Category 2023 2022 Accounts payable $ 235 $ 186 Accrued payroll 6 45 Accrued interest 8 7 Accrued dividend 29 --- Total $ 278 $ 238

Note 11 - Business Segment In_2

Note 11 - Business Segment Information (Tables)	3 Months Ended
	Mar. 31, 2023
Notes Tables
Schedule of Segment Reporting Information, by Segment [Table Text Block]	March 31, 2023 BioLargo ONM Clyra BLEST Water BETI Elimination Total Revenue $ — $ 3,543 $ 6 $ 363 $ — $ — $ (170 ) $ 3,742 Intersegment revenue — — — (170 ) — — 170 — R&D expense (189 ) — (134 ) (245 ) (135 ) (32 ) 170 (565 ) Operating income (loss) (799 ) 1,387 (426 ) (368 ) (184 ) (87 ) — (477 ) Grant income — — — — 31 — — 31 Interest expense (36 ) (2 ) (10 ) — — — — (48 ) Net income (loss) (835 ) 1,385 (436 ) (368 ) (153 ) (87 ) — (494 ) March 31, 2022 BioLargo ONM Clyra BLEST Water Elimination Total Revenue $ 2 $ 600 $ 10 $ 545 $ — $ (188 ) $ 965 Intersegment revenue (2 ) (2 ) — (188 ) — 192 — Research and development (265 ) — (16 ) (108 ) (197 ) 194 (392 ) Operating loss (1,220 ) 13 (240 ) (35 ) (228 ) — (1,710 ) Grant income — — — — 5 — 5 Interest expense (6 ) — (7 ) — — — (13 ) Net income (loss) (1,226 ) 187 (247 ) (35 ) (223 ) — (1,544 ) As of March 31, 2023 BioLargo ONM Clyra BLEST Water BETI Elimination Total Tangible assets $ 530 $ 3,392 $ 578 $ 505 $ 223 $ 628 $ (73 ) $ 5,783 Right of use (leased assets) 114 — — 723 — — 837 Investment in South Korean joint venture 27 — — — — — 27 Total $ 671 $ 3,392 $ 578 $ 1,228 $ 223 $ 628 $ (73 ) $ 6,647 As of December 31, 2022 BioLargo ONM Clyra BLEST Water Elimination Total Tangible assets $ 669 $ 2,064 $ 631 $ 441 $ 194 $ (41 ) $ 3,958 Right of use (leased assets) 136 — — 731 — — 867 Investment in South Korean joint venture 33 — — — — — 33 Total $ 838 $ 2,064 $ 631 $ 1,172 $ 194 $ (41 ) $ 4,858

Note 1 - Business and Organiz_2

Note 1 - Business and Organization (Details Textual)	3 Months Ended
	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)	Sep. 30, 2017
Number of Wholly-Owned Subsidiaries	5
Revenue from Contract with Customer, Including Assessed Tax	$ 3,742,000	$ 965,000
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(494,000)	(1,544,000)
Net Cash Provided by (Used in) Operating Activities	(43,000)	(1,140,000)
Working Capital (Deficit)	3,075,000
Assets, Current	4,874,000		$ 3,153,000
Stock Issued During Period, Value, New Issues	800,000	$ 1,202,000
Cash and Cash Equivalents, at Carrying Value	3,264,000		$ 1,851,000
SBA CARES Act Paycheck Protection Program [Member]
Long-Term Debt	140,000
Economic Injury Disaster Loan [Member]
Long-Term Debt	150,000
Inventory Line of Credit [Member] | Clyra Medical Technologies [Member]
Long-Term Line of Credit	247,000
Vehicle Loan [Member]
Long-Term Debt	78,000
The 2020 Unit Offering [Member]
Stock Issued During Period, Value, New Issues	695,000
Lincoln Park Capital Fund, LLC [Member]
Stock Issued During Period, Value, New Issues	$ 105,000
BioLargo Engineering, Science & Technologies, LLC [Member]
Noncontrolling Interest, Ownership Percentage by Parent	82.25%			100%
Clyra Medical Technologies [Member]
Noncontrolling Interest, Ownership Percentage by Parent	58%
Noncontrolling Interest, Increase from Subsidiary Equity Issuance	$ 225,000
BioLargo Energy Technologies, Inc (BETI) [Member]
Noncontrolling Interest, Ownership Percentage by Parent	97.10%
Noncontrolling Interest, Increase from Subsidiary Equity Issuance	$ 550,000

Note 2 - Summary of Significa_3

Note 2 - Summary of Significant Accounting Policies (Details Textual)		3 Months Ended		12 Months Ended
	Mar. 20, 2020 USD ($)	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)	Jan. 22, 2021 USD ($)
Accounts Receivable, Allowance for Credit Loss, Current		$ 12,000		$ 12,000
Inventory Valuation Reserves		158,000		158,000
Income (Loss) from Equity Method Investments		(6,000)	$ (8,000)
Contract with Customer, Liability		21,000
Contract with Customer, Liability, Revenue Recognized		8,000
Unrecognized Tax Benefits, Ending Balance		$ 0		0
Operating Lease, Weighted Average Remaining Lease Term (Year)		9 years
Operating Lease, Weighted Average Discount Rate, Percent		18%
Operating Lease, Right-of-Use Asset		$ 837,000		$ 867,000
Operating Lease, Liability		844,000
Off-Balance-Sheet, Credit Loss, Liability		$ 0
Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)		3 years
Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)		5 years
Canadian Government Grants [Member] | Minimum [Member]
Grant Term (Month)		6 months
Canadian Government Grants [Member] | Maximum [Member]
Grant Term (Month)		18 months
Odin Co Ltd [Member]
Payments to Acquire Interest in Joint Venture	$ 100,000
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage	40%	40%		40%
Income (Loss) from Equity Method Investments		$ 6,000	$ 8,000
Odin Co Ltd [Member] | Tomorrow Water [Member]
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage	30%
Odin Co Ltd [Member] | BKT and Tomorrow Water [Member]
Payments to Acquire Interest in Joint Venture	$ 150,000
Patents [Member]
Intangible Assets, Net (Excluding Goodwill), Total					$ 34,000
Customer Concentration Risk [Member] | Revenue from Contract with Customer Benchmark [Member]
Number of Major Customers			2
Customer Concentration Risk [Member] | Revenue from Contract with Customer Benchmark [Member] | One Customer [Member]
Number of Major Customers		1
Concentration Risk, Percentage		10%
Customer Concentration Risk [Member] | Revenue from Contract with Customer Benchmark [Member] | Two Customers [Member]
Concentration Risk, Percentage			10%
Customer Concentration Risk [Member] | Accounts Receivable [Member]
Number of Major Customers		1
Customer Concentration Risk [Member] | Accounts Receivable [Member] | One Customer [Member]
Concentration Risk, Percentage		10%

Note 2 - Summary of Significa_4

Note 2 - Summary of Significant Accounting Policies - Summary of Cash Balances (Details) - USD ($)	Mar. 31, 2023	Dec. 31, 2022
Cash and Cash Equivalents, at Carrying Value	$ 3,264,000	$ 1,851,000
Parent Company [Member]
Cash and Cash Equivalents, at Carrying Value	3,171,000	1,685,000
Noncontrolling Interest [Member]
Cash and Cash Equivalents, at Carrying Value	$ 93,000	$ 166,000

Note 2 - Summary of Significa_5

Note 2 - Summary of Significant Accounting Policies - Credit Concentration (Details) - Customer Concentration Risk [Member]	3 Months Ended		12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Customer A [Member] | Revenue from Contract with Customer Benchmark [Member]
Credit concentration	86%	29%
Customer A [Member] | Accounts Receivable [Member]
Credit concentration	70%		24%
Customer B [Member] | Revenue from Contract with Customer Benchmark [Member]
Credit concentration	10%	14%

Note 2 - Summary of Significa_6

Note 2 - Summary of Significant Accounting Policies - Inventory (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Raw material	$ 52	$ 46
Finished goods	83	74
Total	$ 135	$ 120

Note 2 - Summary of Significa_7

Note 2 - Summary of Significant Accounting Policies - Other Non-current Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Patents	$ 34	$ 34
Security deposits	36	36
Tax credit receivable	54	54
Total	$ 124	$ 124

Note 2 - Summary of Significa_8

Note 2 - Summary of Significant Accounting Policies - Stock Options, Valuation Assumptions (Details)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Non Plan [Member]
Risk free interest rate	3.48%
Expected volatility	114%
Expected life in years (Year)	10 years	10 years
Non Plan [Member] | Minimum [Member]
Risk free interest rate		2.32%
Expected volatility		114%
Non Plan [Member] | Maximum [Member]
Risk free interest rate		3.83%
Expected volatility		117%
2018 Equity Incentive Plan [Member]
Expected life in years (Year)		10 years
2018 Equity Incentive Plan [Member] | Minimum [Member]
Risk free interest rate		2.32%
Expected volatility		114%
2018 Equity Incentive Plan [Member] | Maximum [Member]
Risk free interest rate		3.83%
Expected volatility		117%

Note 3 - Sale of Stock for Ca_2

Note 3 - Sale of Stock for Cash (Details Textual) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 13, 2022
Proceeds from Issuance of Common Stock	$ 800,000	$ 1,202,000
Warrants Issued with 2020 Unit Offering [Member] | Maximum [Member]
Warrants and Rights Outstanding, Term (Year)	5 years
Warrants Issued with 2020 Unit Offering [Member] | Minimum [Member]
Warrants and Rights Outstanding, Term (Year)	6 months
The 2020 Unit Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares)	3,656,000	5,196,968
Proceeds from Issuance of Common Stock	$ 695,000	$ 856,000
Lincoln Park Capital Fund, LLC [Member]
Stock Purchase Agreement, Maximum Amount of Common Stock			$ 10,000,000
Stock Issued During Period, Shares, New Issues (in shares)	545,402	1,506,821
Proceeds from Issuance of Common Stock	$ 105,000	$ 346,000

Note 4 - Debt Obligations (Deta

Note 4 - Debt Obligations (Details Textual) - USD ($)					3 Months Ended
	Mar. 06, 2023	Feb. 07, 2023	May 12, 2022	Feb. 07, 2022	Mar. 31, 2023	Mar. 31, 2022	Jul. 31, 2020
Interest Expense, Debt					$ 48,000	$ 13,000
Paycheck Protection Program CARES Act [Member] | ONM [Member]
Extinguishment of Debt, Amount				$ 173,821
Proceeds from Issuance of Debt				$ 217,243
Paycheck Protection Program CARES Act [Member] | BELST [Member]
Proceeds from Issuance of Debt			$ 97,000
Economic Injury Disaster Loan [Member] | ONM [Member]
Interest Expense, Debt					$ 2,000
Debt Instrument, Face Amount							$ 150,000
Debt Instrument, Interest Rate, Stated Percentage							3.75%
Warrant Issued With Conversion of Note [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	200,000
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 0.21
Warrants and Rights Outstanding, Term (Year)	5 years
Conversion of Note into BETI Common Shares [Member]
Debt Conversion, Original Debt, Amount	$ 50,000
Vehicle Loan [Member]
Debt Instrument, Face Amount		$ 80,000
Debt Instrument, Interest Rate, Stated Percentage		5.29%
Debt Instrument, Periodic Payment		$ 1,118

Note 4 - Debt Obligations - Sch

Note 4 - Debt Obligations - Schedule of Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Long-term debt, current	$ 66	$ 100
Debt discount, net of amortization	0	(3)
Total current portion of debt	66	100
Total long-term debt, net of current	302	237
Total	368	337
Vehicle Loan [Member]
Long-term debt, current	13	0
Total long-term debt, net of current	65	0
Paycheck Protection Program CARES Act [Member]
SBA Paycheck Protection Program loan	43	43
SBA Paycheck Protection Program loans, matures May 2025	97	97
Convertible Note, Maturing On March 1, 2023 [Member]
Convertible notes	0	50
Economic Injury Disaster Loan [Member]
Long-term debt, current	10	10
Total long-term debt, net of current	$ 140	$ 140

Note 5 - Share-based Compensa_3

Note 5 - Share-based Compensation (Details Textual) - USD ($)						3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 22, 2022	Jun. 22, 2018	Sep. 07, 2017	Mar. 31, 2023	Mar. 31, 2022
Stock Issued During Period, Value, Issued for Services						$ 207,000	$ 17,000
Share Price (in dollars per share)	$ 0.20					$ 0.20
2018 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)				10 years
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)	50,000,000			40,000,000		50,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized Per Year (in shares)				2,000,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)						1,320,498	2,621,229
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)						$ 0.2	$ 0.23
The 2007 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)					10 years
Non Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)						48,804	32,609
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)						$ 0.20	$ 0.23
Share-Based Payment Arrangement, Option [Member] | Clyra Medical Technologies [Member]
Share-Based Payment Arrangement, Expense						$ 61,000	$ 141,000
Selling, General and Administrative Expenses [Member]
Share-Based Payment Arrangement, Expense						256,000	$ 801,000
Officer [Member]
Stock Issued During Period, Value, Issued for Services						$ 6,000
Stock Issued During Period, Shares, Issued for Services (in shares)						30,747
Shares Issued, Price Per Share (in dollars per share)	$ 0.20					$ 0.20
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Minimum Cash Amount Receipt						$ 3,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Minimum Revenue Required						$ 3,000,000
Consultants [Member]
Stock Issued During Period, Value, Issued for Services	$ 201,000	$ 17,000
Stock Issued During Period, Shares, Issued for Services (in shares)	899,743	86,752
Shares Issued, Price Per Share (in dollars per share)	$ 0.20	$ 0.23				$ 0.20	$ 0.23
Consultants [Member] | 2018 Equity Incentive Plan [Member]
Stock Issued During Period, Value, Issued for Services							$ 97,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)						102,564	447,032
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Fair Value						$ 19,000
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)						$ 0.20
Employees, Consultants, Officers, and Directors [Member] | 2018 Equity Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)						1,320,498	2,621,229
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Fair Value						$ 248,000	$ 564,000
Director [Member] | 2018 Equity Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)						347,730	444,092
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Fair Value						$ 65,000	$ 96,000
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)						$ 0.20	$ 0.23
Employees [Member] | 2018 Equity Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)						570,204	1,690,257
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Fair Value						$ 108,000	$ 362,000
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)						$ 0.20	$ 0.23
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year)						4 years	4 years
Chief Financial Officer [Member] | 2018 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)			10 years
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)			300,000			300,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Fair Value						$ 56,000
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)			$ 0.20
Term Extension (Year)			1 year
Share-based Compensation Arrangement By Share-based Payment Award, Options Grants Per Month, Gross (in shares)			25,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested, Number of Shares (in shares)			25,000
CFO and President [Member] | 2018 Equity Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)							39,848
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Fair Value							$ 9,000
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)							$ 0.23
Vendors [Member] | Non Plan [Member]
Share-Based Payment Arrangement, Expense						$ 9,000	$ 7,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)						48,804	32,609
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)						$ 0.20	$ 0.23

Note 5 - Share-based Compensa_4

Note 5 - Share-based Compensation - Stock Options (Details) - USD ($)		3 Months Ended		12 Months Ended
		Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
2018 Equity Incentive Plan [Member]
Options outstanding, balance (in shares)		28,484,549	23,186,142	23,186,142
Weighted average exercise price per share, balance (in dollars per share)		$ 0.19	$ 0.19	$ 0.19
Options granted (in shares)		1,320,498	2,621,229
Exercise price per share, granted (in dollars per share)		$ 0.20
Weighted average exercise price per share, granted (in dollars per share)		$ 0.2	$ 0.23
Options Unvested (in shares)		(4,073,761)
Weighted average exercise price per share, unvested (in dollars per share)		$ 0.19
Options Vested (in shares)		25,731,286
Weighted average exercise price per share, vested (in dollars per share)		$ 0.19
Vested, aggregate intrinsic value	[1]	$ 678,000
Options outstanding, balance (in shares)		29,805,047	25,807,371	28,484,549
Weighted average exercise price per share, balance (in dollars per share)		$ 0.19	$ 0.19	$ 0.19
2018 Equity Incentive Plan [Member] | Minimum [Member]
Exercise price per share, balance (in dollars per share)		0.12	0.16	0.16
Exercise price per share, granted (in dollars per share)			0.12
Exercise price per share, Unvested (in dollars per share)		0.12
Exercise price per share, Vested (in dollars per share)		0.12
Exercise price per share, balance (in dollars per share)		0.12	0.12	0.12
2018 Equity Incentive Plan [Member] | Maximum [Member]
Exercise price per share, balance (in dollars per share)		0.43	0.40	0.40
Exercise price per share, granted (in dollars per share)			0.23
Exercise price per share, Unvested (in dollars per share)		0.32
Exercise price per share, Vested (in dollars per share)		0.43
Exercise price per share, balance (in dollars per share)		$ 0.43	$ 0.40	$ 0.43
The 2007 Equity Incentive Plan [Member]
Options outstanding, balance (in shares)		1,904,085	2,879,246	2,879,246
Weighted average exercise price per share, balance (in dollars per share)		$ 0.56	$ 0.49	$ 0.49
Options outstanding, balance (in shares)		1,904,085	2,879,246	1,904,085
Weighted average exercise price per share, balance (in dollars per share)		$ 0.56	$ 0.49	$ 0.56
Options outstanding, Expired (in shares)		0	0
Weighted average exercise price per share, Expired (in dollars per share)		$ 0	$ 0
The 2007 Equity Incentive Plan [Member] | Minimum [Member]
Weighted average exercise price per share, balance (in dollars per share)		0.28	0.23	0.23
Weighted average exercise price per share, balance (in dollars per share)		0.28	0.23	0.28
Weighted average exercise price per share, Expired (in dollars per share)
The 2007 Equity Incentive Plan [Member] | Maximum [Member]
Weighted average exercise price per share, balance (in dollars per share)		0.69	0.94	0.94
Weighted average exercise price per share, balance (in dollars per share)		0.69	0.94	$ 0.69
Weighted average exercise price per share, Expired (in dollars per share)
Non Plan [Member]
Options outstanding, balance (in shares)		19,023,829	20,119,207	20,119,207
Weighted average exercise price per share, balance (in dollars per share)		$ 0.39	$ 0.39	$ 0.39
Options granted (in shares)		48,804	32,609
Exercise price per share, granted (in dollars per share)		$ 0.20	$ 0.23
Weighted average exercise price per share, granted (in dollars per share)		$ 0.20	$ 0.23
Options Unvested (in shares)		(507,500)
Exercise price per share, Unvested (in dollars per share)		$ 0.45
Weighted average exercise price per share, unvested (in dollars per share)		$ 0.45
Options Vested (in shares)		18,565,133
Weighted average exercise price per share, vested (in dollars per share)		$ 0.38
Vested, aggregate intrinsic value	[2]	$ 88,000
Options outstanding, balance (in shares)		19,072,633	20,151,816	19,023,829
Weighted average exercise price per share, balance (in dollars per share)		$ 0.39	$ 0.39	$ 0.39
Non Plan [Member] | Minimum [Member]
Exercise price per share, balance (in dollars per share)		0.12	0.12	0.12
Exercise price per share, Vested (in dollars per share)		0.12
Exercise price per share, balance (in dollars per share)		0.12	0.12	0.12
Non Plan [Member] | Maximum [Member]
Exercise price per share, balance (in dollars per share)		0.83	0.83	0.83
Exercise price per share, granted (in dollars per share)
Exercise price per share, Vested (in dollars per share)		0.83
Exercise price per share, balance (in dollars per share)		$ 0.83	$ 0.83	$ 0.83
[1]Aggregate intrinsic value based on closing common stock price of $0.20 at March 31, 2023.[2]Aggregate intrinsic value based on closing common stock price of $0.18 at June 30, 2022.

Note 6 - Warrants (Details Text

Note 6 - Warrants (Details Textual) - USD ($)	Mar. 31, 2023	Mar. 06, 2023	Mar. 31, 2022
Share Price (in dollars per share)	$ 0.20
Note Payable, Maturing March 8, 2023 [Member]
Debt Instrument, Face Amount		$ 50,000
Six-month Warrants in Connection With the 2020 Unit Offering [Member]
Warrants and Rights Outstanding, Term (Year)	6 months		6 months
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)	3,656,000		5,196,968
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 0.228		$ 0.204
Five-year Warrants in Connection With the 2020 Unit Offering [Member]
Warrants and Rights Outstanding, Term (Year)	5 years		5 years
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)	3,656,000		5,196,968
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 0.285		$ 0.25
Warrants Issued in Connection with Conversion of Interest on Note Payable Maturing March 8, 2023 [Member]
Warrants and Rights Outstanding, Term (Year)		5 years
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)		200,000
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)		$ 0.21
Warrants and Rights Outstanding		$ 30,000

Note 6 - Warrants - Warrants Ou

Note 6 - Warrants - Warrants Outstanding (Details) - USD ($)		3 Months Ended
		Mar. 31, 2023	Mar. 31, 2022
Balance, outstanding (in shares)		49,023,398	36,765,562
Granted (in shares)		7,512,000	10,393,936
Expired (in shares)		(4,684,986)	(388,889)
Expired, price range (in dollars per share)			$ 0.22
Balance, aggregate intrinsic value	[1]	$ 122,000
Balance, outstanding (in shares)		51,850,412	46,770,549
Minimum [Member]
Balance, outstanding, price range (in dollars per share)		$ 0.13	$ 0.16
Granted, price range (in dollars per share)		0.21	0.20
Expired, price range (in dollars per share)		0.19
Balance, outstanding, price range (in dollars per share)		0.13	0.14
Maximum [Member]
Balance, outstanding, price range (in dollars per share)		1	1
Granted, price range (in dollars per share)		0.29	0.25
Expired, price range (in dollars per share)		0.35
Balance, outstanding, price range (in dollars per share)		1	1
Weighted Average [Member]
Balance, outstanding, price range (in dollars per share)		0.26	0.27
Granted, price range (in dollars per share)		0.25	0.22
Expired, price range (in dollars per share)		0.21
Balance, outstanding, price range (in dollars per share)		$ 0.26	$ 0.29
[1]Aggregate intrinsic value based on closing common stock price of $0.20 at March 31, 2023.

Note 6 - Warrants - Assumptions

Note 6 - Warrants - Assumptions Used to Determine Fair Value of Warrants (Details)	Mar. 31, 2023	Dec. 31, 2022
Measurement Input, Price Volatility [Member]
Risk free interest rate		0.40
Measurement Input, Expected Term [Member]
Risk free interest rate		3
Minimum [Member] | Measurement Input, Risk Free Interest Rate [Member]
Risk free interest rate	0.0388	0.0369
Minimum [Member] | Measurement Input, Price Volatility [Member]
Risk free interest rate	0.40
Maximum [Member] | Measurement Input, Risk Free Interest Rate [Member]
Risk free interest rate	0.0427	0.0388
Maximum [Member] | Measurement Input, Price Volatility [Member]
Risk free interest rate	0.95
Maximum [Member] | Measurement Input, Expected Term [Member]
Risk free interest rate	5

Note 7 - Accounts Payable and_3

Note 7 - Accounts Payable and Accrued Expenses - Summary of Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Accounts payable	$ 1,039	$ 717
Accrued payroll	160	198
Accrued interest	25	25
Total	1,224	940
Corporate, Non-Segment [Member]
Accounts payable	169	187
Accrued payroll	36	20
Accrued interest	25	25
Total
Operating Segments [Member] | Odor-No-More [Member]
Accounts payable	794	486
Accrued payroll	49	58
Accrued interest	0	0
Total
Operating Segments [Member] | BLEST [Member]
Accounts payable	37	7
Accrued payroll	75	120
Accrued interest	0	0
Total
Operating Segments [Member] | BioLargo Water [Member]
Accounts payable	121	119
Accrued payroll	0	0
Accrued interest	0	0
Total
Consolidation, Eliminations [Member]
Accounts payable	(82)	(82)
Accrued payroll	0	0
Accrued interest	0	0
Total

Note 8 - Noncontrolling Inter_3

Note 8 - Noncontrolling Interest - Clyra Medical (Details Textual) - USD ($)				3 Months Ended		12 Months Ended
	Dec. 20, 2022	Mar. 02, 2022	Jun. 30, 2020	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	Apr. 08, 2022
Preferred Stock, Shares Outstanding (in shares)				0		0
Proceeds from Issuance of Preferred Stock and Preference Stock				$ 225,000	$ 0
Clyra Medical [Member]
Common Stock, Shares, Outstanding, Ending Balance (in shares)						91,149
Shares Issued, Price Per Share (in dollars per share)	$ 310
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)				$ 148.27	$ 1
Clyra Medical [Member] | Vendors and Employees [Member] | Share-Based Payment Arrangement, Option [Member]
Share-Based Payment Arrangement, Expense				$ 61,000	$ 141,000
Clyra Medical [Member] | Employees and Consultants [Member] | Share-Based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Discount Rate				30%
Clyra Medical [Member] | Employees and Consultants [Member] | The Remaining Options [Member]
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)				$ 310
Clyra Medical [Member] | Warrants Issued in Conjunction With the Sale of Series A Preferred Stock [Member]
Warrants and Rights Outstanding, Term (Year)	3 years
Warrants and Rights Outstanding	$ 110,000
Clyra Medical [Member] | Shares Issued for Debt Owed to Biolargo [Member]
Debt Conversion, Converted Instrument, Amount		$ 633,091
Debt Conversion, Converted Instrument, Shares Issued (in shares)		2,032
Clyra Medical [Member] | Series A Preferred Stock [Member]
Preferred Stock, Shares Outstanding (in shares)						2,800
Stock Issued During Period, Shares, New Issues (in shares)	725			725
Proceeds from Issuance of Preferred Stock and Preference Stock	$ 225,000			$ 225,000
Shares Issued, Price Per Share (in dollars per share)	$ 372
Preferred Stock, Dividend Rate, Percentage	15%
Preferred Stock, Convertible, Sale of Stock Amount	$ 5,000,000
Clyra Medical [Member] | Revolving Credit Facility [Member] | Vernal Bay Capital Group, LLC [Member] | Inventory Line of Credit [Member]
Debt Instrument, Interest Rate, Stated Percentage			15%
Line of Credit Facility, Maximum Borrowing Capacity			$ 1,000,000
Proceeds from Lines of Credit, Total			260,000
Repayments of Lines of Credit			$ 113,000
Line of Credit Facility, Covenant, Additional Draws, Maximum Percentage of Total Principal Outstanding Allowed			50%
Line of Credit Facility, Covenant, Additional Draws, Minimum Amount Allowed			$ 200,000
Debt Instrument, Term (Year)			1 year
Line of Credit Facility, Monthly Percentage of Gross Product Sales Required to be Used as Payment of Debt on First 180 Days			30%
Line of Credit Facility, Monthly Percentage of Gross Product Sales Required to be Used as Payment of Debt after the First 180 Days			60%
Stock Issued During Period, Shares, Commitment Fee (in shares)			322			322
Stock Issued During Period, Value, Commitment Fee			$ 70,000
Debt Instrument, Percentage of Principal Payment, Cap						15%
Long-Term Line of Credit				$ 147,000		$ 161,000
Clyra Medical [Member] | Notes Payable, Other Payables [Member]
Debt Instrument, Face Amount							$ 100,000
Debt Instrument, Interest Rate, Stated Percentage							8%
Debt Instrument, Convertible, Sale of Stock Amount							$ 5,000,000
Debt Instrument, Convertible, Conversion Percentage							70%
Vernal Bay Capital Group, LLC [Member] | Conversion of Clyra Medical Stock Into Biolargo Common Stock [Member]
Conversion of Stock, Shares Issued (in shares)				527,983
Clyra Medical Technologies [Member]
Noncontrolling Interest, Ownership Percentage by Parent				58%
Clyra Medical [Member] | Common Stock [Member]
Investment Owned, Balance, Shares (in shares)						51,571
Clyra Medical [Member] | Preferred Stock, Series A [Member]
Investment Owned, Balance, Shares (in shares)						1,352

Note 8 - Noncontrolling Inter_4

Note 8 - Noncontrolling Interest - Clyra Medical - Common Shares Outstanding (Details) - Clyra Medical [Member] - $ / shares	3 Months Ended		12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Options outstanding, balance (in shares)	15,833	14,004	14,004
Balance, Exercise Price Range (in shares)		1	1
Weighted average exercise price per share, balance (in dollars per share)	$ 5.53	$ 1	$ 1
Options granted (in shares)	426	648
Granted, Exercise Price (in dollars per share)		$ 1
Weighted average exercise price per share, granted (in dollars per share)	$ 148.27	$ 1
Options outstanding, balance (in shares)	16,259	14,652	15,833
Balance, Exercise Price Range (in shares)		1
Weighted average exercise price per share, balance (in dollars per share)	$ 9.27	$ 1	$ 5.53
Minimum [Member]
Balance, Exercise Price Range (in shares)	1
Granted, Exercise Price (in dollars per share)	$ 1
Balance, Exercise Price Range (in shares)	1		1
Maximum [Member]
Balance, Exercise Price Range (in shares)	310
Granted, Exercise Price (in dollars per share)	$ 271
Balance, Exercise Price Range (in shares)	310		310

Note 8 - Noncontrolling Inter_5

Note 8 - Noncontrolling Interest - Clyra Medical - Valuation Assumptions (Details)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Clyra Medical [Member] | Vendors and Employees [Member]
Risk free interest rate		2.32%
Expected volatility	40%	40%
Expected life in years (Year)	10 years	10 years
Maximum [Member] | Clyra Medical [Member] | Vendors and Employees [Member]
Risk free interest rate	4.27%
Non Plan [Member]
Risk free interest rate	3.48%
Expected volatility	114%
Expected life in years (Year)	10 years	10 years
Non Plan [Member] | Minimum [Member]
Risk free interest rate		2.32%
Expected volatility		114%
Non Plan [Member] | Minimum [Member] | Clyra Medical [Member] | Vendors and Employees [Member]
Risk free interest rate	3.88%
Non Plan [Member] | Maximum [Member]
Risk free interest rate		3.83%
Expected volatility		117%

Note 8 - Noncontrolling Inter_6

Note 8 - Noncontrolling Interest - Clyra Medical - Summary of Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Accounts payable	$ 1,039	$ 717
Accrued payroll	160	198
Accrued interest	25	25
Accounts payable and accrued expenses, total	1,224	940
Clyra Medical [Member]
Accounts payable	235	186
Accrued payroll	6	45
Accrued interest	8	7
Accrued dividend	29
Accounts payable and accrued expenses, total	$ 278	$ 238

Note 9 - BioLargo Engineering_2

Note 9 - BioLargo Engineering, Science and Technologies, LLC (Details Textual) - USD ($)		1 Months Ended		3 Months Ended		12 Months Ended		25 Months Ended
	Nov. 04, 2019	Jan. 30, 2021	Sep. 30, 2017	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	Dec. 31, 2021	Sep. 30, 2019
Share-based Payment Arrangement, Noncash Expense, Total				$ 256,000	$ 801,000
Percentage of Profits Interests Vested	2.50%	3.75%
Percentage of Option to Purchase Shares of Common Stock	10%	15%
Seven Employees Working at BioLargo Engineering, Science & Technologies, LLC [Member]
Deferred Compensation Arrangement with Individual, Requisite Service Period (Year)			5 years
Potential Ownership Percentage of Subsidiary Held by Subsidiary Employees Based on Performance			30%
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)	175,000	262,500				1,242,500	525,000
Incentive Issuance Stipulations for Subsidiary Employees, Accounts Receivable Collected by Year One of Operation			90%
Incentive Issuance Stipulations for Subsidiary Employees, Profit Earned in Year One of Operation			10%
Percentage of Profits Interests Vested						17.75%	11.25%
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value	$ 44,000	$ 65,000				$ 135,000	$ 65,000
Seven Employees Working at BioLargo Engineering, Science & Technologies, LLC [Member] | Non-Qualified Stock Option [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)			1,750,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year)			5 years
Share-based Payment Arrangement, Noncash Expense, Total								$ 0
BioLargo Engineering, Science & Technologies, LLC [Member]
Noncontrolling Interest, Ownership Percentage by Parent			100%	82.25%

Note 10 - BioLargo Energy Tec_2

Note 10 - BioLargo Energy Technologies, Inc. (Details Textual)	3 Months Ended
	Mar. 31, 2023 USD ($) $ / shares shares
BioLargo Energy Technologies, Inc (BETI) [Member]
Investment Owned, Balance, Shares (in shares)	9,050,000
BioLargo Energy Technologies, Inc (BETI) [Member]
Common Stock, Shares, Outstanding, Ending Balance (in shares)	9,325,000
Conversion From BioLargo Note Payable to Shares [Member]
Debt Conversion, Original Debt, Amount | $	$ 50,000
Debt Conversion, Converted Instrument, Shares Issued (in shares)	25,000
BioLargo Energy Technologies, Inc (BETI) [Member]
Stock Issued During Period, Shares, New Issues (in shares)	50,000
Proceeds from Issuance or Sale of Equity | $	$ 100,000
Stock Conversion, Discount on Volume Weighted average Price	20%
BioLargo Energy Technologies, Inc (BETI) [Member] | Third Party Investors [Member]
Proceeds from Issuance or Sale of Equity | $	$ 550,000
BioLargo Energy Technologies, Inc (BETI) [Member] | Subsidiaries [Member]
Stock Issued During Period, Shares, New Issues (in shares)	325,000
Sale of Stock, Price Per Share (in dollars per share) | $ / shares	$ 2

Note 11 - Business Segment In_3

Note 11 - Business Segment Information (Details Textual)	3 Months Ended
	Mar. 31, 2023
Number of Operating Segments	4

Note 11 - Business Segment In_4

Note 11 - Business Segment Information - Segment Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Revenue from Contract with Customer, Including Assessed Tax	$ 3,742,000	$ 965,000
Intersegment revenue	0	0
Research and development	(565,000)	(392,000)
Operating income (loss)	(477,000)	(1,710,000)
Grant income	31,000	5,000
Interest expense	(48,000)	(13,000)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(494,000)	(1,544,000)
Research and development	(565,000)	(392,000)
Operating income (loss)	(477,000)	(1,710,000)
Tangible assets	5,783,000		$ 3,958,000
Operating Lease, Right-of-Use Asset	837,000		867,000
Investment in South Korean joint venture	27,000		33,000
Total	6,647,000
Total			4,858,000
Investment in South Korean Joint Venture [Member]
Investment in South Korean joint venture	27,000		33,000
Corporate, Non-Segment [Member]
Revenue from Contract with Customer, Including Assessed Tax	0	2,000
Intersegment revenue	0	(2,000)
Research and development	(189,000)	(265,000)
Operating income (loss)	(799,000)	(1,220,000)
Grant income	0	0
Interest expense	(36,000)	(6,000)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(835,000)	(1,226,000)
Research and development	(189,000)	(265,000)
Operating income (loss)	(799,000)	(1,220,000)
Tangible assets	530,000		669,000
Operating Lease, Right-of-Use Asset	114,000		136,000
Total	671,000
Total			838,000
Corporate, Non-Segment [Member] | Investment in South Korean Joint Venture [Member]
Investment in South Korean joint venture	27,000		33,000
Operating Segments [Member] | Odor-No-More [Member]
Revenue from Contract with Customer, Including Assessed Tax	3,543,000	600,000
Intersegment revenue	0	(2,000)
Research and development	0	0
Operating income (loss)	1,387,000	13,000
Grant income	0	0
Interest expense	(2,000)	0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	1,385,000	187,000
Research and development	0	0
Operating income (loss)	1,387,000	13,000
Tangible assets	3,392,000		2,064,000
Operating Lease, Right-of-Use Asset	0		0
Total	3,392,000
Total			2,064,000
Operating Segments [Member] | Odor-No-More [Member] | Investment in South Korean Joint Venture [Member]
Investment in South Korean joint venture	0		0
Operating Segments [Member] | Clyra Medical [Member]
Revenue from Contract with Customer, Including Assessed Tax	6,000
Intersegment revenue	0
Research and development	(134,000)
Operating income (loss)	(426,000)
Grant income	0
Interest expense	(10,000)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(436,000)
Research and development	(134,000)
Operating income (loss)	(426,000)
Tangible assets	578,000		631,000
Operating Lease, Right-of-Use Asset	0		0
Total	578,000
Total			631,000
Operating Segments [Member] | Clyra Medical [Member] | Investment in South Korean Joint Venture [Member]
Investment in South Korean joint venture	0		0
Operating Segments [Member] | BLEST [Member]
Revenue from Contract with Customer, Including Assessed Tax	363,000	545,000
Intersegment revenue		(188,000)
Research and development		(108,000)
Operating income (loss)		(35,000)
Grant income		0
Interest expense		0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest		(35,000)
Research and development		(108,000)
Operating income (loss)		(35,000)
Tangible assets	505,000		441,000
Operating Lease, Right-of-Use Asset	723,000		731,000
Total	1,228,000
Total			1,172,000
Operating Segments [Member] | BLEST [Member] | Investment in South Korean Joint Venture [Member]
Investment in South Korean joint venture	0		0
Operating Segments [Member] | BioLargo Water [Member]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Intersegment revenue	0	0
Research and development	(135,000)	(197,000)
Operating income (loss)	(184,000)	(228,000)
Grant income	31,000	5,000
Interest expense	0	0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(153,000)	(223,000)
Research and development	(135,000)	(197,000)
Operating income (loss)	(184,000)	(228,000)
Tangible assets	223,000		194,000
Operating Lease, Right-of-Use Asset	0		0
Total	223,000
Total			194,000
Operating Segments [Member] | BioLargo Water [Member] | Investment in South Korean Joint Venture [Member]
Investment in South Korean joint venture	0		0
Operating Segments [Member] | BioLargo Energy Technologies, Inc (BETI) [Member]
Revenue from Contract with Customer, Including Assessed Tax	0
Intersegment revenue	0
Research and development	(32,000)
Operating income (loss)	(87,000)
Grant income	0
Interest expense	0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(87,000)
Research and development	(32,000)
Operating income (loss)	(87,000)
Tangible assets	628,000
Operating Lease, Right-of-Use Asset
Total	628,000
Operating Segments [Member] | BioLargo Energy Technologies, Inc (BETI) [Member] | Investment in South Korean Joint Venture [Member]
Investment in South Korean joint venture
Operating Segments [Member] | Clyra Segment [Member]
Revenue from Contract with Customer, Including Assessed Tax		10,000
Intersegment revenue		0
Research and development		(16,000)
Operating income (loss)		(240,000)
Grant income		0
Interest expense		(7,000)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest		(247,000)
Research and development		(16,000)
Operating income (loss)		(240,000)
Operating Segments [Member] | BioLargo Engineering, Science & Technologies, LLC [Member]
Intersegment revenue	(170,000)
Research and development	(245,000)
Operating income (loss)	(368,000)
Grant income	0
Interest expense	0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(368,000)
Research and development	(245,000)
Operating income (loss)	(368,000)
Intersegment Eliminations [Member]
Revenue from Contract with Customer, Including Assessed Tax	(170,000)	(188,000)
Intersegment revenue	170,000	192,000
Research and development	170,000	194,000
Operating income (loss)	0	0
Grant income	0	0
Interest expense	0	0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	0	0
Research and development	170,000	194,000
Operating income (loss)	0	$ 0
Consolidation, Eliminations [Member]
Tangible assets	(73,000)		(41,000)
Operating Lease, Right-of-Use Asset	0		0
Total	(73,000)
Total			(41,000)
Consolidation, Eliminations [Member] | Investment in South Korean Joint Venture [Member]
Investment in South Korean joint venture	$ 0		$ 0

Note 12 - Commitments and Con_2

Note 12 - Commitments and Contingencies (Details Textual) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Sep. 30, 2022
Operating Lease, Expense	$ 83,000	$ 63,000
Operating Lease, Weighted Average Remaining Lease Term (Year)	9 years
Lessee, Operating Lease, Discount Rate	18%
Westminster, California Facility Lease [Member]
Lessee, Operating Lease, Renewal Term (Year)	4 years
Oak Ridge, Tennessee Facility Lease [Member]
Operating Lease, Weighted Average Remaining Lease Term (Year)			10 years

Note 13 - Subsequent Events (De

Note 13 - Subsequent Events (Details Textual) - USD ($)		1 Months Ended	3 Months Ended
	Dec. 20, 2022	May 12, 2023	Mar. 31, 2023	Mar. 31, 2022
Proceeds from Issuance of Common Stock			$ 800,000	$ 1,202,000
Proceeds from Issuance of Preferred Stock and Preference Stock			$ 225,000	$ 0
Clyra Medical [Member]
Shares Issued, Price Per Share (in dollars per share)	$ 310
Series A Preferred Stock [Member] | Clyra Medical [Member]
Stock Issued During Period, Shares, New Issues (in shares)	725		725
Proceeds from Issuance of Preferred Stock and Preference Stock	$ 225,000		$ 225,000
Shares Issued, Price Per Share (in dollars per share)	$ 372
Subsequent Event [Member] | Clyra Medical [Member] | Warrant [Member]
Warrants and Rights Outstanding, Term (Year)		3 years
Shares Issued, Price Per Share (in dollars per share)		$ 372
Subsequent Event [Member] | Series A Preferred Stock [Member] | Clyra Medical [Member]
Stock Issued During Period, Shares, New Issues (in shares)		401
Proceeds from Issuance of Preferred Stock and Preference Stock		$ 124,000
Lincoln Park Capital Fund, LLC [Member]
Stock Issued During Period, Shares, New Issues (in shares)			545,402	1,506,821
Proceeds from Issuance of Common Stock			$ 105,000	$ 346,000
Lincoln Park Capital Fund, LLC [Member] | Subsequent Event [Member]
Stock Issued During Period, Shares, New Issues (in shares)		567,713
Proceeds from Issuance of Common Stock		$ 101,000