Danner 05040 P-4000 Pressurized Filter for 4000-Gallons Ponds Pressurized filter for 4000-gallons ponds Features a unique, manually operated agitator for dislodging over 90 percent of the pond residue that accumulates in the filter chamber This patent pending feature is employed during the backwash and rinse operation For pumps of 1200 to 4000-GPH with 20-feet maximum pumping height 1/2-inch threaded fittings, ball valves for waste line and swivel fitting included