Could you give me more details? I let one of my water pumps run all
winter
but think the air pump might be better, less electric anyway? What size
air pump and where do you get them? I have
about 1000-1200 gal pond.

You can buy an inexpensive aquarium pump at any pet (read GF store) as long
as you protect it from the elements with a rain/snow proof container - I use
an Optima by Hagen and a small Rubbermaid container - just make sure the
airline has no low hanging loops for moisture to collect in and freeze
during thaw/freeze cycles
an airpump uses about 5 watts of electricity, a 1200 gallon water pump
about 150 watts as well as being more expensive to replace or repair. In the
really cold stretches, use a stick to *tap* the thin ice dome that forms ,
or hot water on a regular basis (daily) - if it gets too thick, you will
have a problem (been there done that!!!!)
Gale :~)