Filters ponds over 700 sq. ft. and 10,000 gallons. Creates a perfect base for building beautiful, leak-free waterfalls Requires only once-a-year cleaning when used in combination with a skimmer pre-filter. A non-clogging swirl chamber allows even distribution of water, aiding filtration and increasing waterfall width. Can be sunk into the ground for a stream effect or raised to create a greater water drop Large volume capacity, one of the largest biological filters on the market today (holds more bacteria which means cleaner ponds) . A built-in rock ledge allows this unit to be completely camouflaged out of sight. Remove the check valve at the pump and the discharge acts as bottom drain to empty the BIOFALLS Filter support rack holds filter mats and doubles as side supports . Simple, uncluttered design. No moving parts to break down.