Sandy, yes my fish stay out all year round. We put in heaters to keep the skimmer from freezing solid and run a hose and pump circulating the water to keep it oxygenated. The ice can be from several inches thick to 2'. 2' doesn't leave much liquid in the pond but they have survived it. Makes circulating it more important. I still see some small ones under the thin ice barely moving. The larger ones disappear into a lower cave and won't be seen til spring. they wait for the little ones to come out to be sure it is safe. Or they are more deeply asleep.
