eBay

used this last winter for a couple of months, no longer needed , Fitting a heater to your pond is probably on of the best things you can fit. It will give your fish temperature stability with is proven to keep them heather. You will also be able to enjoy your hobby in to the cooler months

The AquaForte ProfiHeater can be used for heating your pond water. The ProfiHeater is equipped with an adjustable thermostat (up to 40 º C). Both the heating element with temperature sensor and the interior of the housing is made of high grade 316L stainless steel.

The Profi Heater has a fully calibrated Thermostat, so you can easily control the temperature of the pond water.
The Profi Electric Pond Heaters are easy to install into your existing pipework. The Profi Electric Pond Heaters now come with couplings on the inlet and outlets allowing you to remove the heater from the pipework to aid cleaning of the heater element.
Comes complete with cable.
Simple to fit into your system
Profi Heaters will appeal to all pond keeper’s who like to enjoy their Koi hobby during the winter months by increasing the pond water temperature keeping the Koi active.
The Profi Pond Heater incorporates a stainless steel inner lining to the SS electric heating element, with a sturdy remote thermostatic controller box.