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Pool pH Calculator

Enter your current pH and we'll tell you the exact dose to bring it back to the ideal 7.5 — using your real alkalinity and acid strength, not a generic chart.

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Balance your whole pool at once →Enter all your readings on one screen and get an ordered dosing plan — the full Water Report.

How to use it

  1. Test your pool's pH and total alkalinity with a kit or strips.
  2. Enter both, plus your pool volume and the strength of your acid.
  3. Add about three-quarters of the recommended dose, let it circulate, then re-test before adding more.

Why alkalinity matters for pH

Total alkalinity is pH's buffer — it's the reason a splash of acid doesn't crash your pH. The higher your alkalinity, the more acid it takes to move pH the same amount, which is why a calculator that ignores alkalinity gives you the wrong dose. We factor it in.

Acid vs. soda ash

To lower pH, use muriatic acid (or dry acid). To raise it, soda ash works fast but also raises alkalinity — if your alkalinity is already fine, simply aerating the water (running features, jets up) raises pH without touching it.

Frequently asked questions

How much muriatic acid lowers pool pH?
It depends on your alkalinity and volume — higher alkalinity needs more acid. For a 20,000-gallon pool at 100 ppm alkalinity, roughly 20–25 fl oz of 31.45% muriatic acid lowers pH about 0.3. Enter your numbers above for an exact dose.
What is the ideal pool pH?
7.4 to 7.6, with 7.5 the sweet spot — comfortable for swimmers and where chlorine works efficiently without being corrosive or scale-forming.
Should I lower alkalinity or pH first?
Adjust alkalinity first if it's far out of range, since it drives pH. If both are only slightly high, lowering pH with acid will pull alkalinity down a bit too.

Related calculators

Built & reviewed by a working pool-service pro. Target ranges follow CDC MAHC, PHTA, and Taylor guidance. Doses are starting estimates — add a little less than the max, re-test, and confirm against your product label. Educational tool, not a substitute for a water test or professional advice.