Can't believe I've had no offers for the chagoi or benigoi.
This is the heat pump I'm selling.
http://www.dreamheatpumps.co.uk/8kw_heat_pump_HOME.html
I've added a digital thermostat so can be controlled in your filter house.
Only wanting £280 for it and can be seen working. It's a cheap way to heat the pond and low wattage so can be plugged into a normal 3pin plug.