Back when I had an 8 acre pond down south, my aeration system used 6 diffusers. In winter there was rarely any ice cover, but I would turn off the deepest 2 diffusers to reduce cold water stress on the fish.

My new pond up north is only 4 feet deep. If I don't run a diffuser in winter I'm concerned about low DO under ice cover. If I do run a diffuser in winter, I'm concerned about low temperatures at the bottom of the pond.

Is there a way to limit ice cover without reducing bottom temperatures in a very shallow pond?