Spa Boss pH Stable is an easy-to-use product that maintains a stable pH in your hot tub water. It does this by preventing the pH range from drifting erratically. Not only does this simplify the balancing of water, but it also reduces the demand for numerous other water balance products. At the same time, pH Stable softens the hot tub water by eliminating the dissolved calcium that is present. This water softening action thereby improves water clarity. Also, stains which are caused by dissolved metals in the water are less likely to form.