PurigenÂ® is a premium synthetic adsorbent that is unlike any other filtration product. It is not a mixture of ion exchangers or adsorbents, but a unique macro-porous synthetic polymer that removes soluble and insoluble impurities from water at a rate and capacity that exceeds all other competing products by over 500%. PurigenÂ® controls ammonia, nitrites and nitrates by removing nitrogenous organic waste that would otherwise release these harmful compounds. Purigenâ€™s impact on trace elements is minimal. It significantly raises redox. It polishes water to unparalleled clarity. PurigenÂ® darkens progressively as it exhausts, and is easily renewed by treating with bleach. PurigenÂ® is designed for both marine and freshwater use.