Pond Boss Forums INTRO Questions & Observations major winter kill

It seems that despite the sunlight you might not have had enough dissolved oxygen in the pond for the long, cold winter.

Some members use continuous shallow water aeration during the winter months to maintain a small area of open water. You may find that the ice thickness is still good except immediately adjacent to the hole.

Others intermittently aerate to allow for gas exchange and then shut it off again to permit complete re-freezing. I believe Bill Cody does this -- send him a private message on the forums if he doesn't respond soon.