Fluval Aquarium Clear out Foam Blocks provide mechanical straining of particulate waste. It prevents particulate waste from upfront clogging other Clear out media within the module stack. Even if the main purpose of Fluval Foam is mechanical filtration, biological activity will ultimately happen inside its pore structure. These Fluval Aquarium Clear out Foam Blocks also strengthen biological filtration and are suitable for the Fluval 104 and Fluval 105 Aquarium Filters.
Provides mechanical filteration of enormous particles
Prevents premature clogging
Enhances biological filtration
2-pack; Suitable for Fluval 104/105 Clear out