The Fluval Bio Stratum Fish Substrate promotes a healthy environment in your aquariums. It helps to maintain ideal conditions for plant development, growth and vibrant colors. It’s infused with nitrifying bacteria that, once they come into contract with water, work to break down waste and kickstart the nitrogen cycle. The substrate helps to quickly reduce ammonia levels and stabilize the water in new aquariums. The lightweight granules won’t compact, so it’s easy for even delicate roots to work their way into and spread through the substrate. The porous granules let that helpful bacteria grow and also help to filter water to keep it clean.