API® FUNGUS CURE fish remedy effectively treats fungus (Saprolegnia spp. & Achlya spp.), mouth fungus (Cotton Mouth Disease), and Fin & Tail Rot infections. Quickly controls contagious fungal infections. Helps prevent the growth of fungus on fish eggs prior to hatching. For use in freshwater aquariums. Note: This fish remedy will cause a slight discoloration of water which can be removed with activated carbon. This product is not recommended for use with invertebrates and plants as some species may be sensitive to medication.