Fluval Foam Filter Blocks provide effective first-stage mechanical filtration for Fluval 404/405/406 model filters. These foam blocks are custom-fit to trap large particles and debris, with an ideal pore size to allow efficient water passage and prevent clogging.

• Traps particles and debris for mechanical filtration
• Pore size allows efficient water passage with less clogging
• Safe for freshwater and marine aquariums
• For Fluval 404/405/406 filters

The additional filter surface area provided by this foam also enhances biological filtration.