Maintain a healthy and clear pond with TetraPond Clearchoice Biofilters. Ornamental fish can overload a pond ecosystem with ammonia and other pollutants. ClearChoice biofiltration removes these contaminants and ammonia using its advanced Trickle Flow and Bio Ring technologies. Trickle Flow filtration is up to 5 times more efficient than filtration in which the media is submerged, allowing the Tetra ClearChoice filters to be smaller in size for a given pond size. Easy out-of-pond accessibility and simple maintenance. Mechanical pre-filter sponges-remove suspended debris to improve water clarity. Bio Ring media provide massive surface areas for beneficial aerobic bacteria to adhere to and multiply. Aerobic bacteria eat the ammonia toxins created by fish waste and decomposing plant materials. TetraPond internal spray systems and Trickle Flow technology disperses pondwater slowly and evenly through the Bio Rings ensuring that there is sufficient oxygen to provide optimal biofiltration conditions. 1.25" drain fitting Interchangeable .75", 1" intake fittings Venturi inlet aerates water and thus enhances bio-activity -------------------------------------------------------------------------------- PF-3 (for larger ponds) Use with 2400 gallon Water Gardens (or with 1500 gallon Koi Ponds) Dia. 15.25" Ht. 22.5" Maximum flow-1000 gallons per hour -------------------------------------------------------------------------------- PF-2 (for medium ponds) Use with 1800 gallon Water Gardens (or with 1000 gallon Koi Ponds) Dia. 15.25" Ht. 17.5" Maximum flow-750 gallons per hour -------------------------------------------------------------------------------- PF-1 (for small ponds) Use with 1200 gallon Water Gardens (or with 500 gallon Koi Ponds) Dia. 15.25" Ht. 12.5" Maximum flow-500 gallons per hour