As long as your windmill is working and pumping air to an open water area at the surface, your small pond should be okay oxygen wise. I am taking measurements and learning that cold water of winter mixes very easily compared to summer temperatures. I think your working windmill is mixing large volumes of water in your small pond and expanding oxygenated zone pretty far from the diffuser. Come back to this thread when the ice melts and let us know how the fish community survived. Is the windmill diffuser centrally located in the deep area?

Last edited by Bill Cody; 03/05/15 10:01 AM.
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