Powerful non-chlorine shock for your spa or hot tub. Use Blitz shock weekly to eliminate contaminants in your spa and to restore the water to a clear, fresh look. Can be used in conjunction with Go Brom as part of a two part sanitation system that is completely chlorine free. Active Ingredient is Potassium Monopersulfate. Recommended dosage rate is 2 ounces per 500 gallons of spa or hot tub water, or more frequently during periods of heavy bather loads.