Fluval Ammonia Remover is a natural ion-exchange media designed to remove toxic ammonia as water passes over it. Controlling ammonia levels reduces stress on fish. Use this product to provide a healthy environment when setting up a new aquarium or maintaining one that contains a higher than average fish stock.Key Features :Chemical filter mediaControlling ammonia levels creates a safe environment and reduces stress on fishParticularly useful when setting up a new aquarium or for those with heavy fish stockIdeal for use with most canister filtersConvenient 1,600 g (56.43 oz) formatFor freshwater use only