How often you shock spa water depends on the sanitizer used and the bather load. If you are using the 2-part bromine sanitizing system such as Rendezvous ENHANCE and ACTIVATE, it is recommended that you shock each time you finish using your spa. If you are using chlorine or bromine tablets, it is recommended that you shock at least one time per week. It may be necessary to shock more often if the bather load is heavy or the water is cloudy.