We live in SW Ontario and our pond is approximately the same size as yours.
We leave the pump running in the winter and cover the pond with a clear,
heavy plastic tarp. Unless we get a really long super cold snap, the water
stays open and the fish are fine. We have never lost any fish during the
winter and they even seem to grow!
Good luck!
Carolyn

"cymric" wrote in message
...

I live in the Chicagoland area and have a new pond. Its about 2-3 feet
deep in the middle and about 7 feet across. I have six goldfish and
one Koi and wonder if they can overwinter or do I need to bring them
inside?




--
cymric