Fluval 404 Foam Block 2 Pack provides excellend mechanical straining of particulate waste and prevents premature clogging and interference with other filter media inside teh MOdule Stack of the Fluval 404. Designed for mechanical filteration purposes, these high quality foam blocks also provide a place for biological activity to occur within its pore structure.
Instructions: The Fluval Foam must be rinsed as needed (roughly monthly) to retain biological activity. Make sure that you rinse in aged aquarium water to not lose activity. Note that Fluval Foam will deterioriate over time and eventually must be replaced.
Size: 11.5″ l x 3″ w x 1″ h each