Specialized filtration medium in a convenient pouch that eliminates cloudy water caused by phosphate and silicate. Phos-Zorb removes these common nutrients and enhances the growth of hard and soft corals in saltwater. Phos-Zorb also removes compounds that inhibit plant growth in freshwater aquariums. Removes phosphate & silicate For freshwater, saltwater and reef aquariums Size: 1 Pack, Size 6 (Fits most filters)