Fluval BIO-FX Biological Aquarium Fish Tank Filter Media 5Ltr\nFluval BIO-FX is a premium biological media designed for use with canister filters and sumps of all sizes, including Fluval\u2019s flagship FX series. BIO-FX features a deep pore structure with interconnected micro-tunnels, which offers a vast surface area where billions of beneficial nitrifying bacteria can thrive. Linked cavities permit free and even water flow, helping to prevent blockages and prolong contact time for superior and effective biological filtration. Fluval BIO-FX creates the perfect environment for the establishment of a high concentration of nitrifying bacteria to reduce ammonia and nitrite quickly and efficiently for a healthier aquarium. Usage:For most aquariums, 1 filter basket layer of Bio-FX is adequate. For higher bio loads, additional Bio-FX can be used\n\nFluval BIO-FX Biological Aquarium Fish Tank Filter Media 5Ltr\n\nFluval BIO-FX is a premium biological media designed for use with canister fily