Fluval Biological Cleaner (Waste Control, 8.4 oz) uses a blend of beneficial bacteria to consume and break down organic waste in aquariums. By digesting excess fish waste, uneaten food, and sludge in gravel, it reduces aquarium maintenance and helps keep water clearer. Regular use of this natural cleaner lowers ammonia and nitrite buildup and creates a healthier, cleaner environment for fish by controlling organic debris and odors.