SpaGuard® pH Decreaser – Granular Spa pH Reducer (22 oz)

SpaGuard® pH Decreaser is a granular treatment formulated to safely lower high pH in spa water. High pH makes water cloudy, reduces how effectively your sanitizer works, and can cause scale to form on the spa shell, heater, and plumbing — so getting it back into range matters for both comfort and equipment life.

The active ingredient is sodium bisulfate, typically 90–95% of the formula, with a small amount of sodium sulfate. Add it gradually according to the dosing chart on the label to bring pH down into the ideal 7.2–7.6 range, running the jets to circulate it fully before retesting. This 22 oz container works with any sanitizer system — chlorine, bromine, ozone, salt, or mineral — since it only affects pH, not sanitizer chemistry.

Sodium bisulfate can cause eye and skin irritation, so handle it with care and never mix it directly with chlorine or ammonia-based products. Wait until the product has fully dissolved and pH has been retested before re-entering the spa.

High pH doesn't just feel uncomfortable on skin and eyes — it also encourages calcium and other minerals to fall out of solution, which is what causes cloudy water and the early stages of scale on the spa shell, heater element, and plumbing. Because pH and total alkalinity interact closely, check alkalinity first: correcting alkalinity into the 80–120 ppm range often nudges pH back toward normal on its own, and adjusting pH before alkalinity is in range can mean re-treating more than necessary.