Hi git1fiddle ~
Part time aeration should be fine as long as the water volume is turned over enough in that time period. I think you would be better off running the system for 12 straight hours at night and letting the sunlight increase dissolved oxygen durring the day through photosynthesis. I don't think you'll get very good results running it in short stints through out the day like you are planning. If you feel like experimenting, I would be interested in the results, but I think you will just be releasing nutrients into the water column and feeding your algae with out ensuring enough DO to bind those nutrients to the bottom sediments.
Amanda's test sight was very deep ~ I think close to 30'. She went to the site with Scotty Tucker yesterday and did and did an oxygen profile on the Winston Park Lake. The aeration system has been turned off and the lake was stratified at 9' with the majority of the water column anoxic. Our next test on this lake will be to size it for 1/2 a turn over per day or one turn over every other day and see how that affects the water quality. The industry standard is to circulate the volume once per day, but there is a company now recomending 1/2 that, so lets see if it works...
