Overwintering goldfish in Manitoba

[kien]

Have a look through the pond forum. There are a few guys that keep their fish in the pond all winter long and they employ various strategies. You are on the right track with the trough heater although that may be wicked expensive to run over the winter. Keeping an air stone is a good idea. You could always try to keep the water moving with a magdrive (or similar) pump near the surface. A pond deicer is also a good idea to help keep a hole in the ice to allow gas to escape over the winter. Any gas trapped under the ice will most definitely kill all your fish.