I live in Saskatchewan ,Canada and the winters are very cold here.I mean -20
to -30 c on average .I have been putting my large koi inside in the past but
now they are too big.My pond is apr 600 -750 gal with 2 1/2 feet at the
deepest and I would like to try a de icer.Anyone out there in cold canada
that has tried this please help,thanks.