The Boyd Enterprises Chemi-Pure Blue Nano is specially created for fantastic results in reef and marine nano aquariums. This new proprietary blend of premium, low-dust pelleted carbon and high capacity ion-exchange resins are skillfully combined to create a superior all-in-one filter media in a nylon bag. Chemi-Pure Blue significantly reduces organic compounds and phosphates while raising redox and helping stabilize pH for a healthy, crystal clear aquarium. Includes three pre-packaged 22 gram Chemi-Pure Blue Nano bags. 22 grams treats 5 gallons. Replace every four months.