01
The purpose
What does this calculator estimate?
How much baking soda to raise total alkalinity, or acid to lower it, into the 80–120 ppm range.
Water Chemistry · B4
Pool Alkalinity (TA) Calculator
How much baking soda to raise total alkalinity, or acid to lower it, into the 80–120 ppm range.
Measure the inputsTotal alkalinity buffers pH — get TA in range first, then fine-tune pH.
Read the full resultBaking soda (sodium bicarbonate) is the safe, standard way to raise TA.
Check the boundaryTo lower TA, add acid in a concentrated slug to the deep end, then aerate hard.
Useful forWater ChemistryPlanningComparisonVerification
Live calculation
Alkalinity adjustment
✓ Checked May 2026
Enter current and target total alkalinity.
Recommended dose
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Enter the required values to calculate.
Enter the known values. Let the engine handle the calculation.
✓ Formula checked↻ Live result○ No account needed
Planning estimate only. Confirm product labels, equipment specifications, qualified-professional advice and local requirements before acting.
The result, explained
Use the Pool Alkalinity (TA) Calculator result with context.
How much baking soda to raise total alkalinity, or acid to lower it, into the 80–120 ppm range.
02
The tool
What information does it use?
- Pool volume: enter a measured or verified value
- Current total alkalinity: From your test kit, in ppm.
- Target total alkalinity: Ideal range is 80–120 ppm.
- Lower TA with: Acid lowers both TA and pH.
03
The method
How to use this calculator
- Pool volumeEnter the value you can verify.
- Current total alkalinityFrom your test kit, in ppm.
- Target total alkalinityIdeal range is 80–120 ppm.
- Lower TA withAcid lowers both TA and pH.
04
The relationship
The formula in plain English
Raise: Dose = (TA change ÷ 10) × (Volume ÷ 10,000) × 22.4 oz baking soda
To lower TA, add acid to the deep end and aerate to bring pH back up without re-raising TA.05
Worked through
A worked example: 15,000 gal pool, raise TA 70 → 100 ppm
- TA increase = 100 − 70 = 30 ppm
- Dose = (30 ÷ 10) × (15,000 ÷ 10,000) × 22.4 oz = 100.8 oz
- 100.8 oz ÷ 16 = ~6.3 lb baking soda, broadcast across surface
| Pool volume | Baking soda | Raises TA by |
|---|---|---|
| 5,000 gal | 0.7 lb | 10 ppm |
| 10,000 gal | 1.4 lb | 10 ppm |
| 15,000 gal | 2.1 lb | 10 ppm |
| 20,000 gal | 2.8 lb | 10 ppm |
| 25,000 gal | 3.5 lb | 10 ppm |
| 30,000 gal | 4.2 lb | 10 ppm |
06
Why it matters
How the result supports the next decision
Total alkalinity buffers pH — get TA in range first, then fine-tune pH.
Baking soda (sodium bicarbonate) is the safe, standard way to raise TA.
07
Good inputs
Improve the estimate before relying on it
- Total alkalinity buffers pH — get TA in range first, then fine-tune pH.
- Baking soda (sodium bicarbonate) is the safe, standard way to raise TA.
- To lower TA, add acid in a concentrated slug to the deep end, then aerate hard.
- Aeration raises pH without raising TA — the key trick for fixing high alkalinity.
- Re-test 6 hours after adding baking soda so it fully dissolves and circulates.
08
The boundary
How to interpret the result
Follow the product label, add chemicals separately and retest before another dose.
The engine reports invalid inputs and safety warnings beside the result. Resolve those messages before using the estimate.
09
Before acting
What should override this estimate?
- Measured site conditions and current test results
- Product labels and manufacturer specifications
- Qualified-professional advice and applicable local codes
10
Common questions
Frequently asked questions
What does total alkalinity do in a pool?
Total alkalinity is the water's buffer against pH swings. With TA in the 80–120 ppm range, pH stays stable and easy to manage. Too low and pH bounces around unpredictably; too high and pH tends to climb and resist correction.
How do I raise total alkalinity?
Add sodium bicarbonate — ordinary baking soda. Roughly 1.5 lbs per 10,000 gallons raises TA about 10 ppm. Broadcast it across the pool with the pump running and re-test after several hours of circulation.
How do I lower total alkalinity?
Add acid, which lowers both TA and pH. Then aerate the water to bring pH back up while leaving TA reduced. Repeat the acid-then-aerate cycle until TA reaches target. This is the standard professional method.
Why do I adjust alkalinity before pH?
Because alkalinity controls how stable pH is. If you fix pH while TA is wrong, the pH won't hold. Setting TA into range first gives you a stable buffer, after which small pH corrections actually stick.
Will baking soda cloud my pool?
It can briefly if you dump it in one spot, but broadcasting it across the surface with the pump running avoids cloudiness. Any temporary haze clears within a few hours as it dissolves and the filter runs.
How much baking soda to raise alkalinity 10 ppm?
About 1.4 lbs per 10,000 gallons. For a 15,000-gallon pool, that's roughly 2.1 lbs to raise TA by 10 ppm.
Does lowering pH lower alkalinity?
Yes. Any acid you add to lower pH also lowers total alkalinity. That's why the two are always managed together.
What is the ideal alkalinity for a pool?
80–120 ppm for most residential pools, with around 100 ppm a good target. Saltwater pools often aim for the lower end, 70–90 ppm.
Primary sources
Use the result with current guidance.
These official references support safe planning context. Product labels, local requirements and qualified-professional advice take priority over a general calculator estimate.