Total alkalinity calculator
Total alkalinity is pH’s shock absorber. Enter your current and target alkalinity and pool volume to get the exact amount of baking soda to add (or acid to lower it).
How much baking soda to raise alkalinity?
About 1.4 lb of baking soda (sodium bicarbonate) per 10,000 gallons raises total alkalinity by roughly 10 ppm. This calculator scales that exactly to your volume and target. Baking soda nudges pH up only slightly, so it’s the right tool for raising TA.
Raise alkalinity before pH
Alkalinity stabilizes pH, so set it first. If alkalinity is too low, pH bounces around unpredictably; too high and pH drifts upward and water can cloud. Bring TA into range, then fine-tune pH.
Lowering alkalinity
There’s no “alkalinity reducer” — you lower TA with acid (which also lowers pH), then aerate to recover pH. The calculator shows the acid amount when your target is below your current reading.
Ideal ranges
| Level | Target | Notes |
|---|---|---|
| Chlorine pool | 70–120 ppm | |
| Saltwater pool | 60–90 ppm | Lower limits pH drift |
| Hot tub / spa | 50–90 ppm |
Frequently asked questions
Baking soda or soda ash?
Baking soda (sodium bicarbonate) raises alkalinity with minimal pH change. Soda ash (sodium carbonate) is for raising pH and raises alkalinity as a side effect.
Will baking soda raise my pH?
Only slightly. It mainly moves alkalinity, which is exactly what you want when TA is low.
Related calculators & guides
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