Seachem Purigen 250 ml removes proteins, nitrites, nitrates, ammonia and a broad spectrum of organic substances Purigen is a synthetic absorption agent that is different from other filtration products. It is NOT a mix of ion exchangers or other absorption agents, but a unique macroporous synthetic polymer that removes soluble and insoluble impurities from the water at a speed and capacity that exceeds all other products by more than 500%. Purigen removes proteins, nitrites, nitrates, ammonia and a broad spectrum of organic substances, but the impact on trace elements is minimal. It increases the redox. It makes the water clear to unprecedented clarity. Purigen becomes darker in color when it becomes saturated and can be activated again simply by domestic bleaching. Purigen has been developed for both seawater and freshwater use. Application Rinse before use. Use an always fine mesh filter bag to use the 250 ml Purigen well. Each 250ml treats up to 1000 liters of water up to 6 months. Exhaustion can be recognized by a clear change in color to the dark blue / black of the pearls.