Natural Chemistry Spa Oxidizing Shock is a powerful shock oxidizer that quickly eliminates all non-living organic contaminants in hot tub and spa water, yet doesn't add any chlorine to your system. Its oxygen-based formula is gentle on spa surfaces and dissolves fast to start clearing your water. Spa Oxidizing Shock is compatible with both chlorinating and brominating sanitation systems. Natural Chemistry is an industry innovator in utilizing natural enzymes and compounds to clean and sanitize spa and pool water, allowing you to buy with confidence.