Mardel CopperSafe Saltwater and Freshwater Medication is a broad spectrum aquarium medicine formulated to fight off ick velvet and other external parasites. It effectively keeps aquarium water clear of parasites for up to one month. For ick velvet and other external parasites Saltwater and freshwater medication Treats water for 1 month CopperSafe is safe to use with UV Sterilizers Protein Skimmers WetDry and Diatomaceous earth filters. After treatment Coppersafe can be removed from the aquarium by water changes fresh activated carbon or other chemical filtration resinspads. Directions For each size use 5mL for 4 gallons of water. Treats water for 1 month. Chelated copper treatment is recommended for the treatment of ick flukes anchor worms velvet protozoan diseases and other external parasites.