SpaGuard’s Soft Soak Spa Conditioner gives hot tub owners a one-step treatment that prevents and controls the oil build-up that can cause waterline stains. At the same time, its granulated pellets are concentrated enough to only require a single application to your spa upon start-up after your spa is drained and refilled. Soft Soak Spa Conditioner replaces the product formally known as Soft Soak Waterline Control.