Broad Spectrum liquid medication is will cure your fish that are suffering from ulcers or if they have visible crustacean parasites on them. It can also be used to prevent or stop your fish from flicking or scraping against objects. This product contains potassium permanganate which is used only when your fish are suffering from visible conditions. Always aerate water when treating fish with this product. This medication will also temporarily treat green water in your pond, leaving it crystal clear. Broad spectrum should never be used in conjunction with other medication.