Clorox Spa® All-in-One Sanitizer & Shock is a multifunctional granular product that does several things simultaneously. Bacteria can multiply in a spa that isn t well-maintained due to the dark humid environment. The All-in-One Sanitizer & Shock fast-dissolving formula will destroy contaminants and clear cloudy water. Test your spa water frequently to maintain a pH balance of 7.2-7.6 and alkalinity of 80-125ppm for plaster spas and 125-150 for vinyl or fiberglass spas.