Malachite Green is an effective medication used for the control of various external parasites of freshwater and marine fishes. When used as directed the medication will control or prevent the following common protozoan parasites: Ichthyophthinus (freshwater Ich), Costra, Chilodonella, Ambiphyra, Cryptocaryon (marine Ich), Epistylis, Oodinium and Trichodina. Kordon's Malachite Green is also effective against common external fungal infections of fishes and eggs which include Achlya and Saprolegnia. An extensive body of literature supports its use as an effective agent in the control of fungus on fish eggs. Treats up to 240 gallons.