100 % Organic Algae Magic stimulates oxygenation, eliminating the food sources for annoying algae blooms. Enhances the clarity of aquarium water. Algae Magic allows desired plant growth to deal with tank waste more effectively thus maintaining better oxygenization. As the aerobic conditions in the tank are increased and predominate, unwanted algae will still exist, but in lesser quantities. Good for eliminating such nuisance algaes as: green hair, brown diatom and red slime. Will not harm fish, plants, corals, rock or any other tank inhabitants. Does not contain copper sulfate.