MasterTool

Pool Alkalinity Calculator

Calculate the baking soda dose that raises total alkalinity to your target for your pool volume.

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What this tool does

Calculate the baking soda dose that raises total alkalinity to your target for your pool volume. Dosing constant from published alkalinity charts: 1.4 lb sodium bicarbonate per 10,000 gal raises TA ≈10 ppm. Product is assumed 100% sodium bicarbonate.

How to use the Pool Alkalinity Calculator

  1. Enter or select pool volume in gal.
  2. Enter or select current total alkalinity (ppm).
  3. Enter or select target total alkalinity (ppm).
  4. Read the calculated result; change any measurement to compare alternatives.

Formula

baking soda (lb) = pool gallons ÷ 10,000 × (target − current ppm) ÷ 10 × 1.4 lb per 10 ppm per 10,000 gal
volume
Pool volume (gal, before metric conversion)
current
Current total alkalinity (ppm)
target
Target total alkalinity (ppm)

Dosing constant from published alkalinity charts: 1.4 lb sodium bicarbonate per 10,000 gal raises TA ≈10 ppm. Product is assumed 100% sodium bicarbonate.

Worked example

For pool alkalinity calculator, the following measurements illustrate the exact method: Pool volume: 15000; Current total alkalinity (ppm): 70; Target total alkalinity (ppm): 100.

Inputs

  • Pool volume15000 gal
  • Current total alkalinity (ppm)70
  • Target total alkalinity (ppm)100

Result

  • Baking soda (sodium bicarbonate) to add6.3 lb
  • Baking soda to add (oz)100.8 oz
  • Alkalinity increase (ppm)30

Results explained

Baking soda (sodium bicarbonate) to add
Baking soda (sodium bicarbonate) to add from the formula above, expressed in lb before metric conversion. Dosing constant from published alkalinity charts: 1.4 lb sodium bicarbonate per 10,000 gal raises TA ≈10 ppm. Product is assumed 100% sodium bicarbonate.
Baking soda to add (oz)
Baking soda to add (oz) from the formula above, expressed in oz before metric conversion. Dosing constant from published alkalinity charts: 1.4 lb sodium bicarbonate per 10,000 gal raises TA ≈10 ppm. Product is assumed 100% sodium bicarbonate.
Alkalinity increase (ppm)
Alkalinity increase (ppm) from the formula above. Dosing constant from published alkalinity charts: 1.4 lb sodium bicarbonate per 10,000 gal raises TA ≈10 ppm. Product is assumed 100% sodium bicarbonate.

Frequently asked questions

Standard published dosing rule: 1.4 lb of sodium bicarbonate per 10,000 gallons raises total alkalinity by about 10 ppm. The dose scales linearly with volume and with the ppm increase needed.

Baking soda (sodium bicarbonate) is the alkalinity raiser — it lifts TA with only a small effect on pH. Soda ash mainly raises pH. This tool doses bicarbonate for alkalinity.

A commonly recommended range is 80–120 ppm total alkalinity, with many guides favouring 70–90 ppm for salt and plaster pools managed with liquid chlorine. Follow your surface and sanitizer guidance.

Alkalinity is pH's buffer: low TA makes pH bounce around, high TA makes pH drift stubbornly upward and can cloud water or scale surfaces.

Broadcast the powder around the deep end with the pump running, brush any residue, and re-test after a full circulation (about a day) before adding more.