Enjoy true tranquility in your spa with the help of Sirona™ Spa Down. The granular formula lowers pH and total alkalinity levels in hot water to increase the effectiveness of your sanitizer. – Always maintain the pH of your spa water between 7.2-7.8. A high pH (above 7.8) can cause scaling and/or cloudy or colored water – Compatible with all sanitizers Size: 2.5 lbs.