hi
i have a koi pond about 5000 gallons
i would like to heat it using solar power
i live in the sw UK
I have thought about using domestic central heating radiators painted black
and using the pump in the colder months to pump the pond water round and
back into the pond
Idealy id just like to keep the pond 5 or 6 deg warmer so as it will never
freeze
any suggestions or sites i could look at would be usefull

thankx
Dave