Pond boss® Pressurized Pond Filter is ideal for use in ponds up to 900 gallons. This conveniently designed filter is easy to assemble. The pressurized filter combines mechanical and biological filtration by helping water move quickly through the filter so debris doesn’t settle in your pond. BioBalls 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.