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How to Raise pH in a Pool
Soda ash raises pH fast. Two answers give how much to add.
1 of 2: your gallons
Your dose appears here after the last question.
- 7.2
- below this, raise pH
- Soda ash
- sodium carbonate
- Aeration
- raises pH without alkalinity
To raise pH in a pool, test your water first, and if pH reads below 7.2, add soda ash. You want the water sitting at 7.4 to 7.6, though anything between 7.2 and 7.8 will do. | Step | Value | |---|---| | Add soda ash when the reading is | below 7.2 | | Dose per 10,000 gallons, 7.2 to 7.5 | 1 lb 1 oz of soda ash (495 g) | | Test again | 30 minutes after the soda ash goes in | | Aim for | 7.4 to 7.6 | These amounts assume US gallons. Got 20,000 gallons? Use twice as much. A 5,000 gallon pool needs half.
Pool pH too low
Your test strip or kit shows a low pH when it reads under 7.2. Anything from 7.2 to 7.8 is acceptable, so you only have to act when the number drops below that line.
Soda ash is what fixes it. It's worth checking total alkalinity too. Your test shows it in parts per million (ppm), which is simply how much of a chemical is in the water. The range to aim for is 80 to 120 ppm. Baking soda does this job: for every 10,000 gallons of water, 1 lb 6 oz of it lifts alkalinity by 10 ppm.
Adding soda ash
- 1. Weigh out the right amount for your pool size.
- 2. Switch the pump on so the water keeps moving and carries the chemical around.
- 3. Add the soda ash a little at a time in front of a return jet. One chemical at a time, no mixing.
- 4. Give it 30 minutes, then test. If pH is still low, you can add more.
| pH now | 10,000 gal | 15,000 gal | 20,000 gal | 30,000 gal |
|---|---|---|---|---|
| 7.0 | 2 lb 5 oz | 3 lb 7 oz | 4 lb 10 oz | 6 lb 14 oz |
| 7.1 | 1 lb 10 oz | 2 lb 7 oz | 3 lb 4 oz | 4 lb 14 oz |
| 7.2 | 1 lb 1 oz | 1 lb 10 oz | 2 lb 3 oz | 3 lb 4 oz |
| 7.3 | 10 oz | 16 oz | 1 lb 5 oz | 1 lb 15 oz |
Common questions
Is baking soda a way to raise pH in a pool?
Baking soda mainly works on alkalinity, and it belongs in your pool when alkalinity reads under 80 ppm. Test pH again afterward before deciding whether more chemicals are needed.
High pH, low alkalinity: what now?
If alkalinity is below 80 ppm, baking soda can raise it. Test pH again afterward before deciding whether it needs an adjustment. Two safety notes: never mix acid with chlorine, and always pour acid into water rather than water into acid.
Fixing it if you go too far
Dropping from 7.8 to 7.5 calls for roughly 9 fl oz of 31.45% muriatic acid for each 10,000 gallons of water, assuming alkalinity is normal. Wait 30 minutes, then test again.