Added to aquarium water, the powerful oxidizing action of HaloShield attacks and destroys microorganisms that can cause disease in fish. Use for treating fungus, ick, red streaks, milky or shedding slime, flukes, bacterial gill disease, mouth and fin rot, clamped or torn fins, and ulcers. Lifeguard may also be used as a preventive when adding new fish. Package contains 32 tablets.