PhosBan from Two Little Fishies is a favored chemical filter media because it will not leach substances back into your aquarium. Largest adsorption capacity of any phosphate filtering media. Ferric oxide hydroxide-based granules also adsorb organics and other pollutants. Use just like activated carbon; filter bag included. Non-toxic and lasts several months in typical aquariums. Great for saltwater and freshwater aquariums. For best results, use with a TLF Phosban Reactor 150 or 550. Phosphate removing filter media permanently removes phosphate Non-toxic filter media lasts several months in typical aquariums Great for both saltwater and freshwater aquariums Directions: PhosBan can be rinsed briefly before use, but since it is friable, do NOT stir the granules, which would pulverize them. Put PhosBan in a tightly-packed media bag or between two layers of fine filter floss in any kind of flow-through filter or filter chamber so that the water is directed through it diffusely. PhosBan is best used in an up-flow filter such as the PhosBan Reactor, but the flow must be reduced sufficiently to prevent the granules from tumbling, which would grind them into powder. Recommended Usage: 50 g per 50 gal (200 l) saltwater, 50 g per 100 gal freshwater. PhosBan is safe and can be used at more than 5 times the recommended usage quantity, but at high dosages, it can cause a drop in alkalinity. Monitor alkalinity and correct if necessary with buffer or other alkalinity supplements. The useful life of PhosBan depends on the phosphate concentration in the aquarium. PhosBan can be effective for up to several months before it needs to be changed. Replace PhosBan when phosphate levels begin to rise. Contents: Synthetic ferrous oxide hydroxide. 150 gram jar is 0.33 lb, includes a filter bag, and treats 150 gallons. 454 gram jar is 1 lb, includes a filter bag, and treats 450 gallons. 1,200 gram bulk size includes filter bag and treats up to 1,200 gallons.