Thanks for the response. I experienced a major fish kill in July and recently installed a 4 diffuser Kasco aerator and two 3/4hp Kasco surface aerators. All systems are on separate timers. I operate the timers from 10pm to 9:00 am. I was interested to see if DO levels were adequate through the entire water column and maybe need to run the diffuser system a longer period or maybe full time to see if this is occurring.

I have no experience with DO meters and there seems to be concerns as to the durability and difficulty of use with DO meters. I believe my aeration systems are well designed but I do not know how to verify that the water has de-stratified and oxygen level are adequately mixed.

Your expertise is welcomed and any comments on timed aeration will also be appreciated.

Al Allison