Bio-Foam removes particles and debris from aquarium water for effective mechanical filtration. It also serves double duty as a powerful biological media thanks to its ultra dense 30PPI construction, which provides an ideal environment for beneficial bacteria to establish and thrive. Premium biological and mechanical filter media Effectively traps waste and debris Ultra dense 30PPI (Pores Per Inch) foam construction helps maintain even and consistent water flow Ideal surface to promote beneficial bacteria growth Custom fit with no gaps to maximize filtration efficiency For best results, replace every 2 months For use in freshwater and saltwater aquariums