Years of research has led to this advanced pond filtration system from Hozelock. The pond filter is easy to clean as its central core of filter sponges break up during cleaning then reform during use to provide a reliable mechanical barrier for catching debris. The trick is that the filter sponges are not complete blocks but are made up of hundreds of small filter cubes - when the cleaning handle is turned to clean the sponges these move around the chamber and the dirt they have picked up is dislodged. Alongside this cleaning action is a powerful 24w UV unit to zap green algae and K3 Kaldness media to provide bio-cleaning. Complete with a perfectly-matched pump, this set is suitable for goldfish ponds up to 12,000 litres and koi ponds up to 6,000 litres. This set contains the following components (please click links below for more information): • Hozelock Aquaforce 6000 pond pump (note: skimmer not included when purchased in this set). • Hozelock Bioforce Revolution 9000 pressure filter * Saving made when compared to buying items separately.