Fluval Bio-Foam

Biological and mechanical filtration. Filter block for Fluval filter pump. Two pack of replacement foam inserts for Fluval 204 and 304. Provide mechanical straining of particulate waste and prevent it from prematurely clogging other filter media in the module stack. - Foam inserts in sizes for every Fluval - Provide mechanical straining of particulate waste and prevent it from prematurely clogging other filter media in the module stack