Spa Essentials Brominating Concentrate is a spa and hot tub sanitizer. One step fast dissolving brominating granules that act as a sanitizer and an oxidizer. This is a hard-working product that will kill and control bacteria - resulting in water that"s a pleasure to soak in. Spa Essentials brand chemicals are the easiest to use: reach and maintain beautiful spa water. 82.5% Sodium dichloro-s-triazinetrione, 14.7% Sodium bromide.