How to raise the pH in your pool
Doses checked 11/9/2026
Add soda ash (sodium carbonate) in small rounds. The official chart from the Licking County Health Department (Ohio) gives 6 oz to raise pH by 0.2 pH in 10,000 US gallons. Add it with the pump running, wait at least 4 hours, then retest. Stop inside 7.4–7.6, the band in the Licking County Health Department (Ohio) chart.
Checked on every build: 14 tests of the sums this calculator runs, including 1 amount printed in published charts, labels and manuals (ours must match them, or land under them where we start low on purpose) and 4 tests of its limits: caps, smaller rounds, and the cases where it gives no amount.
How much soda ash raises pH
The chart from the Licking County Health Department (Ohio) says Sodium Carbonate (Soda Ash) 6 oz.
for a rise of 0.2 pH in 10,000 US gallons, and the chart from Yakima County (Washington) gives the same: Sodium Carbonate (Soda Ash) 6 ounces
. The calculator scales that to your pool and gives one round at a time.
It never gives more in one round than one maker's label allows. Leslie's, which sells its own soda ash, says Do not exceed 4 lbs per 10,000 gallons in a single treatment to avoid overcorrection.
If your product's label says something different, the label wins.
For example, say your pool holds 20,000 US gallons, the pH reads 7.2 and total alkalinity is 100 ppm. The calculator says to add 12 oz (340 g) of soda ash now, then wait at least 4 hours with the pump running and retest. By the chart, that round should bring pH to about 7.4.
Soda ash vs baking soda
The official charts list soda ash for raising pH and baking soda (sodium bicarbonate) for raising total alkalinity, so this calculator uses soda ash. Retest both readings whichever you add.
Soda ash raises alkalinity too: the chart from Yakima County (Washington) adds this note to its 6 oz amount for 10,000 US gallons: (also raises total alkalinity 5ppm)
. The charts don't give a pH figure for baking soda, so retest both readings after adding either. If both are low, fix alkalinity first, then pH.
Add some, wait, retest
- Test pH and total alkalinity. Alkalinity is adjusted before pH; the Licking County Health Department (Ohio) puts it this way:
if multiple chemical adjustments are required, adjust in the following order: 1) Total Alkalinity 2) Chlorine 3) pH 4) Other Adjustments.
- If total alkalinity is outside 60–180 ppm, fix alkalinity first, wait, retest, then come back to pH.
- Put on the protective gear your label asks for, such as goggles and gloves. Make sure nobody is in the pool, and run the pump.
- Add one round of soda ash as your label directs. Only pre-dissolve it in a bucket if the label tells you to. Add nothing else at the same time.
- Wait at least 4 hours with the pump running, then retest pH.
- Repeat only if pH is still below 7.4. Stop inside 7.4–7.6.
When to ask a pool professional
The calculator gives no amount in these cases.
- Your pH reads 6.8 or lower, or 8.2 or higher. That is the end of a standard test's scale, so the true value is unknown.
- Total alkalinity is outside 40–240 ppm.
- The water is green, black or very cloudy (you can't see the drain at the bottom of the deep end): keep everyone out. The calculator asks how the water looks, and whether the pool is a hot tub or a public or commercial pool, which it doesn't cover.
Questions people ask
How do I raise the pH in my pool?
Add soda ash in small rounds with the pump running. By the official chart, 6 oz raises pH by 0.2 pH in 10,000 US gallons. Wait at least 4 hours, retest, and repeat only if pH is still below 7.4.
Does baking soda raise pH in a pool?
The charts we use list baking soda for raising total alkalinity and soda ash for raising pH, and give no pH figure for baking soda. So this calculator uses soda ash for pH; retest pH as well as alkalinity after adding either.
How much baking soda do I need to raise pH?
We don't give a baking soda amount for pH, because the charts we use list it only for alkalinity. To raise alkalinity, the raise alkalinity calculator works out baking soda; to raise pH, use soda ash.
How much soda ash can I add at once?
The calculator gives one round that raises pH by about 0.2 pH, and never more than one maker's label allows in one go: Do not exceed 4 lbs per 10,000 gallons in a single treatment to avoid overcorrection.
How long after adding soda ash can I swim?
For its own soda ash, Leslie's says You can swim after 4 hours of circulation once the product is fully dissolved.
, and only once free chlorine and pH are back within your label's range. Follow your own product's label.
Add this calculator to your site
Put this code in your own page's HTML. The calculator runs the same sums as this page and links back to us.
The charts behind this page
Show all 13 figures and where each one comes from
Each figure this page and its calculator use. Open one for the source's own words, the other sources we checked it against, and the checks it has been through.
Ideal pH (calculator target band): 7.4–7.6 pH Official
Licking County Health Department (Ohio): Pool and Spa Water Chemistry Adjustment Guide Official says:
pH 7.2 7.4-7.6 7.8
Source page (opens in a new browser tab)Also checked: Multnomah County (Oregon) Environmental Health: Water Treatment - Swimming Pools, EHS-0058 Official says:
Desirable range for pH in pools is 7.2 - 7.6.
Source page (opens in a new browser tab)Also checked: EPA-accepted label: Tarry trichlor 8 oz tablets/sticks (Qualco, EPA Reg. 3525-120) Other source says:
Maintain a pH level of 7.2 to 7.6 for best results.
Source page (opens in a new browser tab)Also checked: Oregon Health Authority: Water Quality Standards, OAR 333-062-1000 (public pools) Official says:
pH 7.0 7.2-7.6 7.8
Source page (opens in a new browser tab)Checked against the source on 11/9/2026. Re-opened by a second checker on 11/9/2026, who matched the source's words to this figure. Looked up again on 11/10/2026 by a checker who couldn't see our figure: it came back with the same figure.
pH range a standard phenol red test reads: 6.8–8.2 pH Other source
Taylor Technologies: Midget Comparator, pH, Phenol Red, 6.8-8.2 Other source says:
Midget Comparator, pH, Phenol Red, 6.8-8.2
Source page (opens in a new browser tab)Checked against the source on 11/9/2026. Re-opened by a second checker on 11/9/2026, who matched the source's words to this figure.
Acceptable total alkalinity range: 60–180 ppm Official
CDC Model Aquatic Health Code, 5th edition (2024), Code Official says:
Total alkalinity shall be maintained in the range of 60 to 180 ppm (mg/L).
Source page (opens in a new browser tab)Also checked: AQUA Magazine Other source says:
Total Alkalinity shall be maintained between a minimum of 60 and a maximum of 180 ppm.
Source page (opens in a new browser tab)Also checked: Oregon Health Authority: Water Quality Standards, OAR 333-062-1000 (public pools) Official says:
Total Alkalinity 60ppm 60-180ppm 180ppm
Source page (opens in a new browser tab)Checked against the source on 11/9/2026. Re-opened by a second checker on 11/9/2026, who matched the source's words to this figure. Looked up again on 11/10/2026 by a checker who couldn't see our figure: it came back with the same figure.
Soda ash (sodium carbonate): oz to raise pH 0.2 in 10,000 US gal: 6 oz per 0.2 pH per 10,000 US gal Official
Licking County Health Department (Ohio): Pool and Spa Water Chemistry Adjustment Guide Official says:
Sodium Carbonate (Soda Ash) 6 oz.
Source page (opens in a new browser tab)Also checked: Yakima County (Washington): Chemical Dosing chart Official says:
Sodium Carbonate (Soda Ash) 6 ounces
Source page (opens in a new browser tab)Checked against the source on 11/9/2026. Re-opened by a second checker on 11/9/2026, who matched the source's words to this figure. Looked up again on 11/10/2026 by a checker who couldn't see our figure: it came back with the same figure.
Soda ash side effect: total alkalinity rise per 0.2 pH step (6 oz per 10,000 US gal): 5 ppm TA Official
Yakima County (Washington): Chemical Dosing chart Official says:
(also raises total alkalinity 5ppm)
Source page (opens in a new browser tab)Also checked: Indiana Department of Health: Adjusting Chemical Levels in a Swimming Pool / Water Chemistry Adjustment Guide Official says:
Sodium Carbonate 14 oz 2.6 lbs 4.4 lbs
Source page (opens in a new browser tab)Checked against the source on 11/9/2026. Re-opened by a second checker on 11/9/2026, who matched the source's words to this figure.
Most soda ash to add in one treatment: 4 lb per 10,000 US gal per stage Other source
Leslie's: Soda Ash pH Up Other source says:
Do not exceed 4 lbs per 10,000 gallons in a single treatment to avoid overcorrection.
Source page (opens in a new browser tab)Checked against the source on 11/9/2026. Re-opened by a second checker on 11/9/2026, who matched the source's words to this figure. Looked up again on 11/10/2026 by a checker who couldn't see our figure: it came back with the same figure.
Order of adjustments: total alkalinity, chlorine, pH, other (calcium, stabilizer, salt) Official
Licking County Health Department (Ohio): Pool and Spa Water Chemistry Adjustment Guide Official says:
if multiple chemical adjustments are required, adjust in the following order: 1) Total Alkalinity 2) Chlorine 3) pH 4) Other Adjustments.
Source page (opens in a new browser tab)Also checked: Leslie's: Muriatic Acid 2-Pack (28%-32%) Other source says:
Always adjust the Total Alkalinity first.
Source page (opens in a new browser tab)Checked against the source on 11/9/2026. Re-opened by a second checker on 11/9/2026, who matched the source's words to this figure.
Circulation time stated on balancer products: 4 hours Other source
Leslie's: Soda Ash pH Up Other source says:
You can swim after 4 hours of circulation once the product is fully dissolved.
Source page (opens in a new browser tab)Also checked: Leslie's: Alkalinity Up Other source says:
Takes around 4 hours for full circulation of Alkalinity Up.
Source page (opens in a new browser tab)Also checked: Leslie's: Dry Acid pH Down Other source says:
You can swim after 4 hours of circulation
Source page (opens in a new browser tab)Checked against the source on 11/9/2026. Re-opened by a second checker on 11/9/2026, who matched the source's words to this figure.
Soda ash: wait before swimming (one product's own page): 4 hours of circulation Other source
Leslie's: Soda Ash pH Up Other source says:
You can swim after 4 hours of circulation once the product is fully dissolved.
Source page (opens in a new browser tab)Checked against the source on 11/9/2026. Re-opened by a second checker on 11/9/2026, who matched the source's words to this figure.
US gallon to liters: 3.785412 L per US gal Official
NIST Special Publication 811, Appendix B.8 conversion factors Official says:
gallon (U.S.) (gal) | liter (L) | 3.785 412 | E+00
Source page (opens in a new browser tab)Checked against the source on 11/9/2026. Re-opened by a second checker on 11/9/2026, who matched the source's words to this figure.
US fluid ounce to milliliters: 29.57353 mL per US fl oz Official
NIST Special Publication 811, Appendix B.8 conversion factors Official says:
ounce (U.S. fluid) (fl oz) | milliliter (mL) | 2.957 353 | E+01
Source page (opens in a new browser tab)Checked against the source on 11/9/2026. Re-opened by a second checker on 11/9/2026, who matched the source's words to this figure.
Ounce (avoirdupois) to grams: 28.34952 g per oz Official
NIST Special Publication 811, Appendix B.8 conversion factors Official says:
ounce (avoirdupois) (oz) | gram (g) | 2.834 952 | E+01
Source page (opens in a new browser tab)Checked against the source on 11/9/2026. Re-opened by a second checker on 11/9/2026, who matched the source's words to this figure.
Pound to kilograms: 0.4535924 kg per lb Official
NIST Special Publication 811, Appendix B.8 conversion factors Official says:
pound (avoirdupois) (lb) | kilogram (kg) | 4.535 924 | E-01
Source page (opens in a new browser tab)Checked against the source on 11/9/2026. Re-opened by a second checker on 11/9/2026, who matched the source's words to this figure.