Pura Carbon media is an acid washed, virgin, activated carbon made from the highest select grades of bituminous coal. Specifically designed for liquid phase applications. It has high adsorption capacity. It is the media of choice in fresh and salt water aquariums to remove large quantities of organic impurities, residual medications, colorants and odors. The lowest ash content of any carbon on the market and maintains high resistance to mechanical degradation. Dust free RO-water rinsed and hydrated. Ideal for the most delicate invertebrates. Maintains high resistance to mechanical degradation. Convenient to implement. This 900-mL carbon media comes with a 6-inch by 12-inch 300-micron media bag.