Reef Endurance ROX 0.8 Carbon 1/4 gallonPremium Activated Carbon Reef Endurance now offers ROX 0. 8 Pharmaceutical Grade Activated Carbon, the finest activated carbon available. These tiny dense extruded pellets produce superior absorption for quicker pristine water clarity with fewer media. Quickly remove yellowing pigments, medications, contaminants, toxins, and other irritants from your aquarium's water. Now offered in four sizes. ROX Features Best performing carbon Wide range of pore