Kordon's 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. Kordon's Malachite Green utilizes the less common but also less toxic chloride salt of malachite green (this is the same salt used in Kordon's Malachite Green). CAUTION: Malachite green can interfere with biological filtration at dosages above 0.10 ppm. Malachite green is toxic to some kinds of scaleless fishes, including catfishes, loaches, small characins (tetras). Care should be taken with sensitive fishes- dwarf cichlids, gouramis, livebearers, barbs. Malachite green can permanently color the silicone sealant in aquariums. If stress develops, remove fish to another untreated aquarium; or, make an immediate partial or complete water change and replace carbon filtration. 4 ounce bottle treats 240 gallons.