Thanks for the input guys! George1: the bottom diffuser is the way I would like to go, and it would have to be a DIY thing. The problem would be supplying power. I could operate that type of system, but only about 1hr a day(if that's good enough, problem solved. if not...$$$$) and Yes, I know of Todd & Overton fisheries(bought bluecat from him last year). TLF: It took me a few minutes to catch what you said. I may be pulling out the stratified water & allowing the bad gasses(ammonia&others)to escape, but I'm still not getting oxygen(or D.O.)down to the bottom. I knew 2 heads(or more) are better than one! I'll study BOD at my next chance. Thanks for the input guys, anyone else care to chime in? I'm all ears!