The AquaClear 50 is for 20 - 50 gallon freshwater and saltwater fish only aquariums.Maximum Output: 200 gallonsFull Flow Control: 66 gphPower Consumption: 6 wattsThe AquaClear is backed by a lifetime guaranteeFlow Control: Simply shift the patented "Flow Adjustment Control" at the the intake siphon. When the "Flow Adjustment Control" is at its greatest blockage, AquaClear's input and exhaust volumes are approximately a third of its maximum capacity. User Manual (pdf file in new window) The AquaClear 50 Power Filter provides mechanical, chemical and biological filtration through its multi-stage filtration system. Filtration volume is up to 7 times larger than comparable Filters. Its unique design filters aquarium water through a natural and silent waterfall. The patented flow control feature allows for customized filter performance. The filter preserves beneficial bacterial creating a stress free environment for aquarium inhabitants and maintains clear aquarium water. Installation and maintenance are quick, easy and convenience. The filter comes equipped with AquaClear Foam, Activated Carbon and BioMax. In addition, AquaClear delivers an entire line of media including Zeo-Carb and Ammonia Remover exclusively designed for the AquaClear Power Filter.