"~ jan" wrote
| If depth is the key, how much do I need?

| Use of a stock tank heater and pond depth isn't that much of a problem
even
| in the coldest places. I'm sure you're familiar with the fact stock tanks
| aren't even in the ground and stock tank heaters keep the water open for
| livestock. I keep one on a remote control so it only runs when it is
really
| cold.

I'd rather not have to use a heater. Still would like to know how to find
out what the "frostline" is.