Marineland Black Diamond Premium Activated Carbon removes discoloration, odors and impurities for sparkling clean aquarium water. Composed of heat-activated, bituminous coal-based carbon, this media is ideal for chemical filtration in all aquarium filters. Black Diamond Premium Activated Carbon granules are specially sized and far more efficient than coconut, wood or peat-based carbons. Ideal for use in all aquarium filters.Clean, sparkling water is the mark of a healthy, thriving aquarium. The amount of filtration needed to maintain an aquarium depends on a number of variables. These include tank size, individual maintenance habits and fish population. Whatever your individual needs, Marineland brand has the filtration products you need to deliver on-target, advanced filtration.