Kent Organic Adsorption Resin removes organic pollutants, stain, and entrained toxic gases to provide a pure environment in marine and freshwater aquariums, like no other product on the market. Makes tanks sparkle! Greatly reduces or eliminates the need for carbon use in aquariums. Even removes the stain from African driftwood that carbon won't touch. Economical to use since it can be regenerated over and over again. Resin life is about 2 years of service. Will not remove trace elements like carbon or other resins will, so it can be left in the system for long periods of time. Will remove nitrates in fresh water. Shipping weight: 3/4 lbs.