Has anyone either heard of or used a technique of using the heat in
your house like either of these:

-Keep your filter in the corner of your basement (or somewhere else in
your house) and run the piping through the exterior wall of your
house. This would serve to heat the water, depending on the flow rate
of your filter.

-Use a tank of some sort to flow water from the pond into the inside
of the house. The flow rate would be such that the water would stay in
the tank a sufficient period of time to warm before being returned to
the pond.

Both of these would obviously require 2 pipes going into/out of the
house. It would not be to keep the water at 70 degrees. It would
merely be to keep it above freezing for those of us in colder areas (I
am zone 5). The bigger the tank, the warmer the water would be. It
seems that other methods of heating are very expensive. I bought one
of those low energy de-icers and my pond froze over before it even got
to be really cold.