What is the recommended pH range for pools, hot tubs, and spas?

• A. 6.5 - 7.5
• B. 7.8 - 8.2
• C. 6.8 - 7.2
• D. 7.2 - 7.8

Answer: (D)

Maintaining pool, hot tub, and spa water within a narrow, near-neutral pH keeps both disinfection and comfort in balance. Chlorine kills pathogens mainly as hypochlorous acid, the more active form, and its predominance is greatest around neutral pH. When the water sits in the 7.2 to 7.8 range, chlorine works effectively while still being gentle on eyes and skin. If the pH drops too low, the water becomes corrosive and can irritate eyes and skin, and metals and equipment may be damaged. If the pH rises too high, the sanitizer becomes less effective and mineral buildup or scaling can occur on surfaces. That combination of strong disinfection, user comfort, and reduced wear on the pool or spa makes 7.2–7.8 the recommended range. Other ranges tend to be too acidic or too basic, compromising either comfort or sanitation.