Spa Choice Reduce pH liquid decreases the pH level when your hot tub water tests as alkaline. The recommended range is 7.4 - 7.8 ppm. In this range, both the spa user and equipment are protected. If the pH levels are not in the acceptable range use Increase pH to make the water more basic or Reduce pH to make the water more acidic. Spa Choice Reduce pH helps avoid damage to spa surfaces and spa equipment by preventing the buildup of scale. Note: Spa Sauna Direct only ships pool and hot tub chemicals within the continental United States.