Two Little Fishies Phosban Media Reactor 150The 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 of water through the media, and prevents channeling. It can be mounted hanging on the back of the aquarium or below the aquarium. Hose barb connections are for 1 2 inch i. d. tubing. Includes 1 2 inch barbed ball