Alkalinity Adjustment Calculator
Calculates baking soda amounts to raise total alkalinity, or muriatic acid with aeration to lower it.
How it works
Raise TA: 1.5 lbs per 10k gal raises TA ~10 ppmLower TA: 26 fl oz muriatic acid per 10k gal lowers TA ~10 ppm + aeration
- You enter
- Pool volume (gallons), current alkalinity (ppm), target alkalinity (ppm), adjustment direction (raise/lower)
- You get
- Baking soda (lbs), acid amount (fl oz), adjustment method, retest timing (hours)
How accurate is it? Lowering TA also lowers pH (aeration can raise pH back); only add baking soda in stages (1.5 lbs max per 10k gal per dose).
These are estimates, not quotes. See How We Estimate.
Worked example
20,000-gallon pool TA 60 ppm, target 100 ppm: Need 100 ppm increase = (1.5 × 20000÷10000) = 3 lbs per 10 ppm, so 6 lbs total.
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
Maintains alkalinity buffer (80-120 ppm) to stabilize pH and prevent swings from daily chemical additions.
Weekly alkalinity balance, after rain dilution, chronic pH drift, opening pools, addressing corrosive or cloudy water.