pex? plastic? it is an insulator. metal is the best conductor. remember, cold
doesnt seep out, heat has to spread in. Ingrid

On Thu, 16 Oct 2008 20:18:00 EDT, Derek Broughton wrote:

wrote:

it would need to be metal and the only thing I would trust in the pond
would be really expensive.

Why would it need to be metal? Radiators for cars or homes are metal
because they need to move a lot of heat, quickly, into air - which doesn't
conduct heat well. Water conducts heat _very_ well, and if you were
running the output from a solar heater through about 40' of 3/4 or 1" PEX
at the bottom of the pond, I think you'd get excellent heat transfer. I'd
check that with a heating engineer, if possible, but I'd bet on it.