Spa Activator is an odorless shock that is the most favored product by hot tub owners whether they use chlorine or bromine. It is a powerful oxidizer formulated to be safe to use after each use of the hot tub whether you are using chlorine, bromine, or mineral purifiers. Spa Activator is a shock not a sanitizer and is extremely effective in eliminating organic contaminants introduced by bathers such as body oils, lotions, urine, etc. along with environmental factors like rain and wind. Essentially it allows sanitizers to more be effective in eliminating bacteria and viruses along with reducing the frequency of adding sanitizers in order to keep a proper ppm level. Best of all it contains no chlorine, unlike bromine, so it is essentially odorless. RECOMMENDED USE Add 2 ounces per 300 gallons of water each time you exit your spa or 2 ounces weekly if the spa has not been used. Make certain filtration pump is active for at least 30 minutes each time you add Spa Activator.