Based on Dantabrom chemistry, these tabs provide a concentrated source of active bromine that is ideal for hot tub sanitizing. These tablets dissolve slowly and evenly and fit in most spa feeders and floaters to provide continuous disinfection of your spa.Before Use:Before using this product in your spa or hot tub for the first time, add 1/2"ounce of sodium bromide per 100 gallons of water to establish a 30 ppm bromide concentration. Also, add sodium bromide at this dosage whenever the spa or hot tub is drained and refilled. The bromide addition ensures immediate establishment of an all-bromide system eliminates chlorinous odors and maximizes skin and eye comfort.Spa or Hot Tub Start-Up:Using a suitable feeder adjusted according to the manufacturer's directions, add this product to maintain an active bromine concentration of 2 to 4 ppm in residential spas and 3 - 6 ppm in commercial spas. Use a reliable test kit to monitor bromine regularly. This product's usage will typically vary from 0.015 to 0.10 pound for every 300 gallons of spa water to maintain the recommended bromine concentration range. The presence of organic debris, high bather use and other factors may require a higher dosage.Super Oxidation:Water soluble, non-filterable wastes can accumulate in spa water and cause dull or cloudy water and can stimulate algal growth. Super oxidation or super chlorination with a suitable oxidizing shock treatment should be done on a regular basis to remove these wastes and maintain clear, sparkling water. Suitable oxidizing agents are those based on calcium hypochlorite, lithium hypochlorite, sodium hypochlorite or potassium peroxymonopersulfate. Do not mix this product in concentrated form with any other chemicals. Do not add other chemicals to the feeding device when using this product. Advantage:Unique chemistry provides the effectiveness of chlorine without the chlorine odor. The low-dusting tablet shape fits most floating feeders to create bromine residual quickly.