Bill; OUCH! I paid about $20 extra for the DO part. After reading the manual, I had some questions but am glad to have your input. It goes back.

I am interested in DO. I had a crash last year that hit a 1/3 acre pond hard. Appears to have wiped out the 25 channel cat I had in it. Also hit the cats in my larger one where I found some floating with bluegills. Is there any way to get a reasonably priced (relatively cheap) DO meter?