API Phos Zorb API PHOS-ZORB filtration media is scientifically proven to remove phosphate and silicate, it also eliminates cloudy water. Phosphate can enter the aquarium in fish waste, decaying organic matter and tap water. High phosphate in the aquarium can cause water clarity issues. Phosphate can be reduced with PHOS-ZORB, a phosphate-removing filter media. 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. Phos-Zorb can be used when testing indicates the presence of phosphate (greater than 0ppm/mg/L) or silicate (greater than 0.5ppm/mg/L). Directions Rinse Phos-Zorb pouch under tap water for several minutes to remove dust and activate the Phos-Zorb. The activation process wil temporarily generate some heat. Place pouch in path of water flow in the aquarium filter. Replace pouch every 2 months or when testing indicates the presence of phosphate or silicate.