ADA filter media bio-rio is the basic of biological filtration. With live bacteria on bio rio, biological filtration starts quickly after the initial setup. Mainly made of pumice stone with a porous surface, which is ideal environment for beneficial bacteria to colonize. It also enables long, stable filtration. The nitrifying process of bacteria is the most phase in nature aquarium filtration systems. In this process, toxic ammonia or nitrous acid are decomposed and become harmless. Bio rio, composed of volcanic stones, provides the ideal home for a long term and stable colonization of bacteria and maintains the conditions of aquarium water.