Yes. That is what I said I believe.
But if I recall what Cody said, the air water interface affects a very small amount of water right at the surface.
If I recall what he said correctly, the majority of DO infusion comes from algae respiration during the daylight hours and produces O2 at all levels the algae see sunlight.
If that is true (and I remember correctly what he said) daylight hours are multiple times more effective at infusing DO into the BOW.
That is why I wonder if night only operation is not short changing the capability of the aeration system to add DO to the BOW. But I also understand the problem of over heating the entire BOW. So it would seem to me there are two different issues that are at odds with each other.
I think I see where you are going with this. Are you saying running aeration during the day the plankton can add O2 to the entire column of water being moved by the aeration? The way I understood it, as soon as the water reaches the air/water interface the exchange happens and the water absorbs all the O2 it can hold. I am probably wrong, but I don't think you are getting any EXTRA O2 from the plankton.
The air/water interface only affects the small amount of water at the surface but with aeration we are constantly exposing thousands of gallons to the surface and every ounce of water in that column that reaches the surface will end up fully oxygenated whether day or night. Great discussion!
Of course water temps, etc are really going to drive a pondmeister's decision to aerate during the day or night. It is still fun to discuss, all else being equal, is day or night more efficient.
