The pond boss Pressurized Pond Filter with UV Clarifier is ideal for use in ponds up to 1,200 gallons. This filter offers maximum cleaning efficiency by utilizing a 9 watt UV clarifier that cleans water with ultraviolet light combined with a pressurized filtration system. The mechanical and biological filtration helps water move quickly through the filter so debris doesnt settle in your pond. Bio balls are utilized to provide a larger surface area to promote the growth of beneficial bacteria while dual filtration pads catch large and small debris. The result, a clean pond with improved water quality that is safe for fish and plants to thrive.