My pond is 24" deep and holds about 250-300 gal. and has 6 goldfish in it. I
live in zone 5 and we get freezes but not usually sustained for too long. I
cleaned it and removed leaves, trimmed plants, etc. in Nov. I stopped
feeding the fish in mid-November. The pond surface has partially frozen two
or three times since Nov. During the day I see the fish swimming near the
surface.

My question is should I stop the filter for the winter or leave it running?
I've read several pond books and I'm still not sure if I should shut it down
and if so, why. Can anyone advise me? Many thanks,
Denise