PH increaser for hot tub spas raises the pH level in hot tubs. Increases the pH level when your spa water tests as acidic. The recommended range is 7.4 - 7.8 ppm. In this range, both the hot tub user and equipment are protected. If the pH levels are not in the acceptable range use pH Up to make the water more basic or pH Down to make the water more acidic. Spa Sauna Direct can not ship orders for pool chemicals or hot tub chemicals outside of the continental United States.