Kordon Copper-Aid External Parasite Treatment is a safe, efficient and effective treatment for the most common external parasites in your aquarium. Its non-staining formula eliminates Ich, velvet, anchor works, flukes, and other parasites that can harm your fish. Copper Aid protects the tank for one full month and can be used in fresh and saltwater aquariums. Non-stainingProtects tank for 1 full monthFor fresh and saltwater aquariums4oz treats 100 gallons of waterEffective treatment for Ich, velvet, anchor works, flukes and other external parasitesDirections for Use: As a treatment for Ich, Velvet and to aid in general external parasite disease prevention, add 1 teaspoon (5 ml) per 4 gallons of water. Treats water for 1 month.