The Two Little Fishies Phosban Reactor 150 is designed with the upflow principle to achieve the most efficient use of PhosBan or other chemical filter media. By pushing water from the bottom upward through a dispersion plate, it forces an even distribution or water through the media, and prevents channeling. The Phosban Reactor 150 can be mounted hanging on the back of the aquarium or below the aquarium. Hose barb connections are for 0.5" I.D. Tubing. Includes 0.5" barbed ball valve for flow control, and hose clamps. Use with any pump having a capacity between 100 and 250 gph, but regulate the flow rate to the recommended 20 to 30 gph with the included ball valve.