***
If I recall correctly, well water typically has a temp of around 62-67*f, so it would definitely help warm your pond.
***
Ground temp is 55*F. I know this because all gas and diesel tanks that are in ground are calibrated to a 55*F temp so you get the correct amount of fuel you pay for at the pump.
So the gas/diesel tanks say from Tennessee and on south have a different calibration for ground temps of 68, 70, 72deg F, etc as you go south?
