Aqua Excellent is an environmentally friendly water care system for your spa or hot tub. Aqua Excellent will help you keep your spa water clean in a safe, simple, and effective way. With just one weekly treatment, Aqua Excellent will help prevent calcium deposits in your system. In addition, Aqua Excellent loosens and eliminates existing calcium deposits. These calcium deposits are the breeding ground for bacteria and other microorganisms. The ozone or UV system already in your spa will do the rest. It destroys bacteria and disinfects the water. The results are extraordinary: your spa water is not only clean, it is also crystal clear and soft to the touch.