Outdoor Pond --- what to do with my KOI???

[DOO-E]

We winter our koi and goldfish in our pond. There is somebody here that has a pond yoursize. All he does is cover it with a few layers of black plastic and put a trough heater in the pond. The water will heat the air and keep the pond warm. But make sure it isnt too warm otherwise you will have to run outside 3 times a day to feed your fish. Sorry forgot to mention make the black plastic into a dome not flat it needs to me in a dome shape.