Seachem Purigen 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 others. Purigen removes proteins, nitrites and nitrates, ammonia, and a broad spectrum of organics, yet its impact on trace elements is minimal. It significantly raises redox and polishes water to unparalleled clarity. Purigen darkens progressively as it exhausts, and is easily renewed by treating with household bleach.