For periodic shocking, use FROG Maintain, it’s one dose in one single easy-to-pour packet for one easy maintenance shock to keep your water crystal clear. No measuring, no guess, no mess. The hot tub is ready in 15 minutes of shocking. Once in the water FROG Maintain quickly dissolves and eliminates organic contaminants. Non-chlorine shock means you get the clean without any Cyanuric Acid, ever.