Pool Alkalinity Calculator Australia
Work out how much sodium bicarbonate (bicarb) to add to raise total alkalinity, then confirm with the free dosing calculator.
Fastest path
Enter your pool type, volume, and total alkalinity reading for an exact recommendation.
Open pool chemical calculatorHow much bicarb to raise alkalinity
Use pool-grade sodium bicarbonate or an alkalinity increaser. The chart below is a practical estimate for Australian backyard pools.
| Pool volume | Raise TA by 10 ppm | Raise TA by 20 ppm |
|---|---|---|
| 30,000 L | 510 g | 1.0 kg |
| 50,000 L | 850 g | 1.7 kg |
| 75,000 L | 1.3 kg | 2.6 kg |
| 100,000 L | 1.7 kg | 3.4 kg |
Example: a 50,000 L pool at 70 ppm TA that needs 90 ppm needs about a 20 ppm lift → roughly 1.7 kg bicarb.
Why alkalinity matters
- Low TA makes pH bounce up and down
- Stable TA helps chlorine and copper systems work more predictably
- Fix TA before fine-tuning pH in most cases
Because alkalinity and pH move together, it helps to calculate your pool chemical doses in one go rather than one reading at a time.
Safe dosing steps
- Test total alkalinity and pH.
- Calculate the bicarb dose from the chart or calculator.
- Pre-dissolve bicarb in a bucket of pool water.
- With the pump running, pour around the deep end.
- Retest after 4–6 hours, then adjust pH if needed.
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