Unique spherical activated carbon allows superior chemical filtration Actively removes dissolved aquarium organic waste material for clean, clear water Outperforms other high grade activated carbons by at least two-fold This activated carbon has a spherical shape for optimum water flow and superior chemical filtration. Water moves through it, not around it, allowing water to come in maximum contact with its highly porous binding sites. Greater contact between water and Matrix Carbon means more organic waste materials being removed before exhaustion. The result is cleaner, clearer aquarium water for a longer period of time. Treats twice as much water for twice as long as most activated carbons! Unlike conventional granular activated carbons, the unique spherical shape prevents compacting or channeling, and Matrix Carbon is very clean and nearly dust-free. Won't affect pH. 200 grams will easily dose 200 gallons for several months. Please click on "More Information" for usage instructions.