At last we have found a box filter to satisfy the more discerning goldfish pond keeper, plus it is even good enough for koi (see reduced pond size figures in section below). This compact multi-bay system employs filter foam cartridges, brushes and flocor media to ensure your dirty pond water is thoroughly filtered. It has a powerful built-in UVC unit under the lid which keeps your water clear of green water, and is a doddle to clean by utilising the quick action back flush. A full de-sludge is also available by simple hose attachment (all filter media is held above the filter floor so valuable friendly bacteria will not be harmed by this process). NOTE: UVC bulbs included.