The Fluval 204/304 Foam Block 2 pack provides mechanical straining of particulate waste. Preventing waste from prematurely clogging or further interfere with your filter media. Although the main purpose of Fluval Foam is for mechanical filtration the poreous structure allows for biological activity eventually.
Instructions: Rinse foam monthly or as needed to retain biological activity. Please note to rinse foam in aged aquarium water to lose as little biological activity as possible. Replace the Fluval 204/304 Foam Blocks alternately so biological activity is not interrupted.
Specifications: Contains 2 Fluval Foam Pads
Size: 8 1/2″ x 2 3/4″ x 1″