SpaGuard’s Soft Soak Stain & Scale Control enables hot tub owners to protect their spas from scale build-up or stain formation, which is common with high amounts of dissolved metals in water. Preventing scale build-up keeps water clear as well as ensuring no filtering system clogging. Soft Soak Stain & Scale Control should only be used with other Soft Soak products. This product comprises part of SpaGuard’s Soft Soak System.