To raise total alkalinity by 10 ppm, add 1.4 lb of baking soda per 10,000 gallons of pool water. That is the figure in Hayward’s chemistry guide for 100% sodium bicarbonate, and it matches the chemistry. For any pool, pounds = (gallons ÷ 10,000) × (ppm increase ÷ 10) × 1.4.
Most pools aim for 80–120 ppm. The Pool & Hot Tub Alliance (PHTA) narrows that by sanitizer: 80–100 ppm for calcium, lithium or sodium hypochlorite (liquid chlorine), and 100–120 ppm for dichlor or trichlor. Its minimum is 60 ppm and its maximum is 180 ppm.
How much baking soda for your pool
These amounts come from Hayward’s Table 3 for 100% sodium bicarbonate (pounds).
| Raise TA by | 10,000 gal | 15,000 gal | 20,000 gal | 25,000 gal |
|---|---|---|---|---|
| 10 ppm | 1.4 | 2.1 | 2.8 | 3.5 |
| 20 ppm | 2.8 | 4.2 | 5.6 | 7 |
| 30 ppm | 4.2 | 6.3 | 8.4 | 10.5 |
| 40 ppm | 5.6 | 8.4 | 11.2 | 14 |
| 50 ppm | 7.0 | 10.5 | 14.0 | 17.5 |
Worked example. A 15,000-gallon pool reads 60 ppm and you want 90 ppm, so you need to raise it by 30 ppm. That takes (15,000 ÷ 10,000) × (30 ÷ 10) × 1.4 = 6.3 lb of baking soda, the same as Hayward’s table. If you are not sure of the volume, work out your pool volume first, or use the pool volume calculator; its estimates are for simple shapes, so use average depth.
Check the reading before you dose
- Correct for stabilizer. Taylor says cyanuric acid (CYA) titrates as total alkalinity when it is above 30 ppm: subtract 1/3 of your CYA reading from the alkalinity reading. A test showing 90 ppm alkalinity with 60 ppm CYA is really about 90 − 20 = 70 ppm. See cyanuric acid in pools.
- Baking soda is for alkalinity, soda ash is for pH. Hayward uses baking soda to increase total alkalinity and soda ash to increase pH. If pH is the real problem, read pool pH too high or too low.
- Know your target. PHTA notes that its ranges do not supersede product label directions or local or state codes and regulations.
How to add it
- Test total alkalinity (and CYA), and confirm the pool volume.
- Work out the dose from the table or the formula. For a big correction, add about half, let the pump circulate the water, and retest before adding the rest. That avoids overshooting.
- Add one chemical at a time. CDC warns that pool chemicals can injure people when mixed together or when appropriate personal protective equipment is not used.
- Do not add calcium chloride the same day. Taylor says adding calcium chloride in the hours before or after treating with baking soda will result in cloudy water. If calcium is also low, see calcium hardness in pool water.
The table and formula assume 100% sodium bicarbonate, so check that an “alkalinity increaser” says so on the label. If its label gives a different strength or rate, the label rate controls. If your alkalinity is too high, see pool alkalinity too high or too low, and for the full routine, the pool water chemistry guide.
Sources
- Hayward: Chemistry Quick Start Guide (Table 3: baking soda to increase total alkalinity)
- Pool & Hot Tub Alliance (PHTA), published by Taylor Technologies: Recommended Water Chemistry Parameters
- Taylor Technologies: Understanding and Managing Calcium Hardness in Pool & Spa Water
- CDC: Pool Chemical Safety
Research checked 2026-10-12.
