This activated carbon is a 50-50 blend of coconut shell based activated carbon and of pelletized carbon. ~Coconut shell based activated carbons have a greater micro-pore structure, which targets the removal of smaller, lower molecular weight contaminates. The best aquarium water purifier and absorber available. This unique formula removes the following; impurities, organics, chloramine, chlorine, fish odors, ammonia, toxic metals, secretions, toxins. It makes yellow water clear and is used for ozone generators to convert ozone to ozygen. Safe and easy to use it will not leech back impurities absorbed from your aquarium and is compatible with uv steralizers. Satisfaction Guarenteed.