The Ocean Clear poly-bead filter from Red Sea® traps particulates and provides surface area for nitrifying bacteria. It will handle small fish loads, so it is suitable for small koi ponds, recirculating systems, quarantine systems, etc. A grid- and funnel-shaped bottom evenly distributes water through 7 lbs (31 ft²) of polyethylene beads. The filter is self-cleaning by backwashing through the drain valve. Dimensions are 15" H x 15" W. Weighs 13 lbs. One-year warranty.