Exhibit 16.1 CACCIAMATTA ACCOUNTANCY CORPORATION 2600 MICHELSON DRIVE, SUITE 490 IRVINE, CA 92612 August 3, 2001 Securities and Exchange Commission 450 Fifth Street, N.W. Washington, D.C. 20549 Re: Sionix Corporation ------------------ Commission File No. 2-85626-D ----------------------------- Dear Sirs: We have read Item 4 of the Current Report on Form 8-K of the Company, dated July 27, 2001, and we agree with the statements contained therein as they related to our firm. Very truly yours, Cacciamatta Accountancy Corporation By /s/ Danilo Cacciamatta ------------------------