What Should a Pool's pH Level Be?
The ideal pH range for swimming pool water is 7.2–7.4. This range keeps chlorine's disinfecting power at its most efficient level, prevents eye and skin irritation, and protects equipment from corrosion. Above pH 7.8, chlorine's effectiveness drops noticeably.
Why Does pH Matter So Much?
pH indicates the acid-base balance of pool water and is the foundation that every other chemical parameter (chlorine, alkalinity, calcium hardness) depends on. Low pH corrodes surfaces and equipment, while high pH causes calcium scaling, cloudiness and filter clogging.
In more than 35 years of field experience, one of the most common operating mistakes we see is raising chlorine dosage without first correcting pH — this wastes chemicals without solving the underlying problem.
How Do You Raise or Lower pH?
Sodium bisulfate (dry acid) or hydrochloric acid is used to lower pH, while soda ash (sodium carbonate) raises it. The correct dosage must be calculated based on pool volume and current pH-alkalinity readings — blind dosing destabilizes the water.
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How often should pH be tested?+
Commercial pools with heavy bather load should be tested at least twice a day; private pools 2-3 times a week.