Sludge caused by a build up of fish and plant waste and uneaten food is unsightly and detrimental to fish health by harbour pathogens and polluting the water. Sludge Gone is designed to digest organic material in the sludge leading to a much cleaner aquarium, reducing the risk of disease and algae growth. Sludge Gone is a blend of enzymes and bacteria which can also support and encourage the activity of the biological filter bacteria. Suitable for tropical and coldwater aquariums