Fluval Biomax, 500 gr. by Hagen

BioMax filter media are inert ceramic rings that are capable of supporting large populations of water purifying bacteria.
Composed of a variety of channels and tunnels, the multitude of tiny pores can support these colonies of beneficial bacteria.
BioMax is an ideal biological filter media that will make the most of any filter system due to its huge capacity to support the organisms responsible for metabolizing ammonia and nitrite.