This dual-action formula from Leisure Time prevents unsightly water line film as well as stain and scale from forming around the perimeter of the spa. With a sequestering agent to prevent stain and scale, Control will help make sure your spa or hot tub stays clean and clear. Start-up Instructions: Control must be added first when filling the spa. Maintenance Instructions: Control is added first during the weekly maintenance program. Compatible with Leisure Time Simple Spa Care specialty line of products and specifically designed to work in the Free biguanide system with Boost Free. About the Brand: Leisure Time was developed for use in spas, hot tubs, and jacuzzies. Our water care products are both economical and powerful enough for the toughest jobs. Within Leisure Time’s wide selection of products, we offer everything from algaecides and deposit control formulas to non-chlorine shock treatments, powerful surface cleaners, clarifiers, enzyme-based cleaners, and more. If you like using Leisure Time, check out some of the other similar brands from our parent company, Sigura. With brands like HTH, Applied Biochemists, GLB, Spa Selections, and PooLife, Sigura has a long heritage and more than a century of experience in developing innovative water treatment solutions for use in pools, lakes, ponds, hot tubs, and more. At Sigura, we have an unparalleled passion, pride, and commitment to delivering superior water treatments that improve the environment and enhance the security, health, and safety of the global communities we serve. With our track record of innovation and simple, intuitive solutions that anticipate needs, Sigura customers feel more secure as they enjoy their pools, spas, ponds, and lakes.