PR-10 000 is the strongest most concentrated phosphate control product available in the aquatics market. It is formulated to react with phosphates in water allowing for them to be removed from solution. It is an all-natural rare earth phosphate removal product. It reacts with orthophosphates on contact crystalizing them. The inert phosphates then sink out of solution to be vacuumed or filtered out. PR-10 000 causes cloudiness in the water for up to two days. Use only as needed.