Fluval U2/U3/U4 BioMax 170g A495 Fluval U2/U3/U4 BioMax Bio Rings Biological Filter Media 170g for Fluval U Series Customer Rating  N/A Add Review Ask Question $7.95 Qty : < > Product Description Reviews (0) (View All) Questions (View All) Fluval BioMax bio rings have a complex pore system creating an optimal environment where beneficial bacteria can thrive. The BioMax  bio rings have more capacity than most biological filter media and allow ideal water movement throughout the media, to ensure optimal contact time for efficient biological filtration. It also reduces and controls ammonia and nitrate. Fluval U2/U3/U4 BioMax is specially designed to fit Fluval U series filters. For freshwater and marine environments. 170g Add Review There are no reviews for this product. Ask Question There are no questions asked for this product. Ok