Ensure your Fluval G filter is operating at its best and help remove excess nitrates with Fluval's G6 Nitrate Adsorbing Cartridge. Fish waste， uneaten food and other organic matter can create toxic levels of ammonia and nitrate. These toxins can cause stress， illness and even lead to fish loss. This cartridge is designed to remove up to 24，000 mg. of nitrate ion in freshwater aquariums. Use this cartridge regularly as part of your aquarium maintenance to control nitrates and pollutants， so you can provide your finned friends with an environment where they can thrive.