Phosphate Zero is a resin based on iron that can remove large amounts of phosphates and silicates from water. It is important to maintain phosphate levels below 0.1 mg/l (ppm) in freshwater and 0.02 mg/l (ppm) in seawater. Phosphate Zero captures phosphates and silicates and as beneficial side effect it releases OH-ions. These ions have the ability to neutralize the acids in excess and to stabilize the pH. For maximum efficiency place a sufficient amount of resin into the filter. Do not immerse the resin in water without first putting it into the filter. This resin unlike others does not require a fluidized bed filter to work properly. Wash briefly in pure freshwater before use. If the resin is not washed it will release dust. Once exhausted it does not release any chemicals.