Good Link Joe, I'll copy it to the original post for easy reference. It, now, makes sense that the pH climbs all day at my pond along with the DO even though I'm not sure why the chart below generically shows ponds peaking at mid afternoon. My BOW must have very good alkalinity as my pH swings are relatively flat and the DO from algae blooms increases as long as there is day light...

I am tempted to turn the aeration system off for one night and check DO levels the next day...I think this coming weekend has a purpose. Any guesses as what I can expect? I think the DO at the surface will be higher than mornings when the air has been running, but the deeper DO levels will be less...drats...back to my question...which is better, good DO levels in the upper few feet OR weak DO levels throughout the water column? Am I chasing the meaning of life?

Last edited by Quarter Acre; 09/23/19 01:25 PM.

Fish on!,