Engineered Foam Products Foam Filter Sponge - 15.5" x 5" x 3"

Engineered foam has the porosity to allow for high levels of beneficial bacterial cultures, as well as the density to allow for efficient mechanical filtration. Engineered foam has a very long life span, as in can be easily rinsed, and re-used. The perfect balance for any aquarium application, engineered foam is completely non-toxic, and 100% safe for both marine and freshwater aquariums.