The OASE Filtoclear 12000 is a UV pressure filter that is suitable for 1500 litres – 4000 litres.
It has an 18 watt UV light which prevents the growth of single-celled algae (responsible for green water!).
The best feature though is the filters easy and effective backwash system. The engineers at OASE patented the simple technology of lifting up the blue handle to squeeze out the sponges. Simple right? Well, no other company can have a pressure filter where the sponges are squeezed out from the inside, meaning that for all other brands, the backwash is next to useless.
This filter should be paired with a solids-handling pump that has a flow of about 11500 litres per hour. We recommend the Aquamax 11500 if you are not pumping the water up to a waterfall after the filter. Maybe consider a stronger pump like an Aquamax 14500 if you are pumping it up to a waterfall up to a metre high.
You should also have a think about how much 40mm hose you might require. You need a piece of hose going from the pump (located in the pond) to the filter (located in a convenient place for access) and then from the filter to the other end of the pond (far away from the pump to encourage full water circulation).