New MultiChamber flow through pond filters offer all the features of similar products costing twice the price!Suitable for goldfish ponds up to 9000 Litres 2000 gallons.Suitable for koi ponds up to 4500 Litres 1000 gallons.Submersible pond pump pushes dirty water up to the box filter via the UVC unit included. The pond filter collects dirt and debris and clean water returns to your pond.New improved version Set now includes an advanced UV unit that sits snugly on the back of the filter box.