[Letterhead]



Securities and Exchange Commission
450 Fifth Street, N.W.
Washington, D.C.  20549


Re:      Hach Company and Subsidiaries
         Registration on Form S-8


Gentlemen:

We are aware that our report  dated  November  20, 1997 on our review of interim
financial  information on Hach Company and  Subsidiaries for the three-month and
six-month  periods ended November 1, 1997, and included in this quarterly report
on Form 10-Q for the three months then ended,  is incorporated by reference into
the  registration  statements of Hach Company and Subsidiaries on Form S-8 (File
No. 33-39019),  Form S-8 (File No. 33-90584),  and Form S-8 (File No. 33-64793).
Pursuant to Rule 436(c) under the Securities Act of 1933, this report should not
be considered a part of the registration  statements prepared or certified by us
within the meaning of Section 7 and 11 of that Act.



COOPERS & LYBRAND L.L.P.


Denver, Colorado
December 12, 1997