• Biological aquarium filter media for superior and effective filtration
• Safe, inert ceramic material
• Designed for use with sump filtration and canister filters of all sizes
• Deep pore structure with interconnected micro-tunnels offers vast surface area
• Linked cavities permit free and even water flow
• Quickly establishes high concentration of nitrifying bacteria for a healthier aquarium
• For best results, rinse monthly using aquarium water and replace partially every 6 months
• For optimal filtration, place in the last stage of the filtration process