Api prevent algae removes phosphate and silicater this clears cloudy water which are caused by these factorsr enhances the growth of hard and soft corals in saltwater and removes compounds that inhibit plant growth in freshwaterr designed to perfectly fit the nexx filterr one box contains 2 pouches each pouch lasts 2 monthsr directionsr 1 rinse pouch under tap water for several minutes to remvoe dust and activate the prevent algaer 2 the cartridge does not need to rinse clearr 3 fit to