0.6L PH 8~8.4 Ceramic Marine fish filter media S 300g Marine fish filter media "S" ( 0.6L / 300g ) PH8.0~8.4 WITH 1PC Filter Net Bag Suitable for freshwater and saltwater aquariums 400 times effective surface and decomposition rate than normal bio-filter ring. Easily detached bio-membrane improves metabolism of beneficial bacteria. Recyclable for plant soil use.