Fluval Biological Enhancer is a responsive biological aquarium supplement that immediately inoculates aquarium water with a powerful team of beneficial bacteria, providing a safe biological habitat for your fish. It goes to work fast, releasing massive amounts of beneficial bacteria that eliminate toxic ammonia and nitrites while creating a biologically well-balanced aquarium for healthy fish to thrive. Fluval Biological Enhancer is strongly recommended for new aquariums, as they do not contain the necessary concentrations of beneficial bacteria required to metabolize the waste that fish produce. It quickly establishes safe and essential conditions in new aquarium setups, so that you can introduce fish to new aquariums immediately. Regular application helps to competitively exclude the establishment of undesirable bacteria in aquariums. Fluval Biological Enhancer provides consistent results thanks to our unique and proprietary bio-floc technology that ensures product stability, efficacy and shelf life. Sizes: 4oz, 8oz