"Rick" wrote in message
nk.net...
I'm using a bubbler and a stock tank heater as a back up if it looks like
the bubbler can't handle the job. Remember you are only trying to keep the
pond from freezing over completely.

Actually, it doesn't even need to keep a hole open in the ice.
The main purpose of the bubbler is to make sure that gases
from rotting vegetation and other wastes do not become
trapped and build up some concentration level of those gases.

If bubbles are being added to the water and they are escaping
somewhere (like around the edges), then they will take the gases
with them.

If the gases are not escaping, the the pond will build up pressure
until it explodes. Stand back! :-) (not really)

Unless your fish need slightly warmer water (and it will only be
slightly), the heater is totally unnecessary and a waste of energy.

I live in northern Colorado. On my little pond the bubbles create
interesting volcano type mounds. When it gets really cold, those
close up and the gases escape around the edges somewhere.

Jerry