Leisure Time Renew Tabs are a non-chlorine shock oxidizer that is conveniently packaged in easy-to-use tablets that quickly dissolve in spa water and break down residual soaps, deodorants, natural oils and organic materials before they have a chance to form combined chlorine.Applications:After Each Use:1. Turn on filtration system.2. For each 250 gallons of water, place 3 tablets into spa water.3. Run filtration system for 15 minutes with cover off.4. Repeat process once a week to help maintain clear, odor-free water.Tips:Using Renew Tabs to shock oxidize the spa after each use will keep the water clean and clear until the next time the spa is used.Compatible With:Chlorine, bromine, ozone and mineral purification systems.