TotalPond Replacement Filter Pads for the 900 Gallon Pressurized Pond Filter (PF850) and 1200 Gallon Complete Pond Filter with UV Clarifier (PF1200UV) Replacement Filter Pads for PF850 and 52236 contain 2 filter pads for use in the Pressurized Biological Filter or Complete Pressurized Pond Filter with UV Clarifier. Includes 2 circular filter pads, 1 coarse and 1 fine. We recommend changing filter pads yearly for optimum cleaning performance. 90 day warranty