"K30a" wrote in message
...
I would leave a little but I would also have a hole open in the ice to let
the
gasses of decomposition escape.

I sink a big 4 or 5 inch PVC "y" connector in the deepest part of the pond
to provide cover for the fish. I have no frogs, so I can't speak to that
issue. I also use a cheapo aquarium bubbler with two airstones to keep the
pond aerated, and a floating donut-type heater to keep a hole open if the
bubbler doesn't.

NJ