PolyGuard is the single most effective medication to keep freshwater fish free of disease! It is an effective treatment and safeguard against all prevalent bacterial, fungal, and parasitic diseases of exotic fish. DIRECTIONS: Use 1 level measure (included) to every 40 L (10 gallon)s. Repeat every 3 days for up to 2 weeks or until symptoms disappear. Use whenever introducing new fish. Easily removed by chemical filtration. Active ingredients: sulfathiazole (75%), malachite green (4%), nitrofurantoin (0.25%), 5-nitro-2-furaldehyde secmicarbazole (0.25%), Quinacrine dihydrochloride (0.5%). Inactive ingredients: magnesium carbonate (20%).