pH Adjustment Calculator
Calculates exact amounts of muriatic acid or soda ash needed to achieve ideal pH range.
How it works
Muriatic Acid (31.45%): 6.4 fl oz per 10k gal lowers pH ~0.1Dry Acid: 9.6 oz per 10k gal lowers pH ~0.1Soda Ash: 6 oz per 10k gal raises pH ~0.2
- You enter
- Pool volume (gallons), current pH, target pH, acid type (muriatic/dry acid), acid strength %
- You get
- Acid dose (fl oz or lbs), soda ash amount, retest timing
How accurate is it? pH affects chlorine effectiveness (7.2 ideal = 63% active; 8.0 = 21% active); always add acid to water, never water to acid; wait 4-6 hours for retest.
These are estimates, not quotes. See How We Estimate.
Worked example
10,000-gallon pool pH 8.0, target 7.4: Using 31.45% muriatic acid: 6.4 × (0.6÷0.1) = 38.4 fl oz needed.
Tap an example above the calculator to see it worked with live numbers.
Reference table
| Reading | Ideal range | Notes |
|---|---|---|
| Free chlorine (FC) | 2–4 ppm | Chlorine that is still working |
| pH | 7.4–7.6 | How acidic or basic the water is |
| Total alkalinity (TA) | 80–120 ppm | Buffers pH so it holds steady |
| Calcium hardness | 200–400 ppm | Protects plaster from etching |
| Stabilizer (CYA) | 30–50 ppm (salt pools 60–80) | Shields chlorine from sunlight |
| Salt (salt pools) | 2,700–3,400 ppm | Check your salt cell's manual |
When to use it
Achieves ideal pH 7.2-7.6 to maximize chlorine effectiveness and swimmer comfort.
Weekly pH corrections, high pH from pool fill water, low pH from acidic sanitizers, opening/closing pools.