The Phosban Reactor 150™ has become a staple amongst most aquarists who keep SPS corals. So much so that you often see Phosban used interchangeably with the term GFO or Granular Ferric Oxide. To meet the demand of larger tanks and reduce the number of Phosban Reactors needed, TLF has created the Phosban 550 reactor for aquariums up to 600 gallons. It can be mounted hanging on the back of the aquarium or below the aquarium. The pump used should have a flow rate of 100-200GPH. Includes ball valve for regulating flow, and flexible connection fittings that rotate 180 degrees to allow a perfect custom fit to your installation. The threaded lid design makes servicing quick and easy. One reactor for aquariums up to 600 gallons. *for activated carbon or GFO/Phosban use ONLY. Specifications Dimensions: 15 1/8 inches tall, 4 1/4 inches diameter For aquariums up to 600 gallons 1/2 inch inlet/outlet