How to Raise Alkalinity in a Pool: Step-by-Step Guide
Buy baking soda (sodium bicarbonate). Add 1.5 lbs per 10,000 gallons for each 10 ppm increase needed. Dissolve in a bucket of pool water first, then pour slowly around the pool with the pump running. Retest after 6-8 hours. We have verified this method against CPO chemical procedures and the TroubleFreePool community’s tested approach. See our complete pool chemistry guide for how this step fits into the full water balance sequence.
If you want to understand why alkalinity drops and what it does to your water before doing the fix, read our companion guide on pool alkalinity low causes and effects first.
Video guide
Video: “Pool Chemistry for Beginners: pH and Alkalinity” by Swim University
What You Need (Tools and Materials)
Here is everything we recommend having on hand before you start:
- Baking soda (sodium bicarbonate): Sold as “pool alkalinity increaser” at pool stores, or as regular baking soda at any grocery store. They are the same chemical. Grocery store versions cost roughly 3-5x less per pound. We find that a 10-lb bag covers most single-session adjustments for a 10,000-20,000 gallon pool.
- Digital kitchen scale or measuring cup: Accuracy matters. Eyeballing baking soda volume produces inconsistent results. A $10 kitchen scale eliminates the guesswork.
- 5-gallon bucket: Required for pre-mixing. Do not add baking soda directly to the pool without dissolving it first.
- Pool test kit or test strips: Get a baseline TA reading before you start. A liquid reagent kit (Taylor K-2006) is more accurate for alkalinity than strips.
- Protective gloves: Optional but recommended. Baking soda is not caustic, but skin sensitivity varies.
How much to buy: Calculate your dose from the table in the next section before purchasing. For a 20,000-gallon pool needing a +30 ppm correction, you need 9 lbs.
How Much Baking Soda to Add (Dosing Table)
The formula: 1.5 lbs of baking soda per 10,000 gallons raises Total Alkalinity by approximately 10 ppm. This is the standard figure from InTheSwim’s chemical dosage charts and is consistent across CPO training materials.
| Target TA Increase | 10,000 gal | 15,000 gal | 20,000 gal |
|---|---|---|---|
| +10 ppm | 1.5 lbs | 2.25 lbs | 3 lbs |
| +20 ppm | 3 lbs | 4.5 lbs | 6 lbs |
| +30 ppm | 4.5 lbs | 6.75 lbs | 9 lbs |
| +40 ppm | 6 lbs | 9 lbs | 12 lbs |
Example: 15,000-gallon pool with current TA at 60 ppm, target is 90 ppm. Need a +30 ppm increase. Add 6.75 lbs of baking soda.
Maximum per session: Do not raise TA more than 20-30 ppm in a single day. Adding more than 30 ppm at once can temporarily cloud your water through calcium carbonate precipitation. The cloudiness clears on its own in 24-48 hours, but avoid it by spreading large corrections over multiple days.
According to TroubleFreePool alkalinity targets{:target=“_blank”}, the right TA target depends on your sanitizer type. Liquid chlorine and SWG users should target 50-90 ppm; tablet users (Di-Chlor, Tri-Chlor) and mainstream guidance targets 80-120 ppm.
Step-by-step: how to add baking soda to your pool
Follow these steps in order. Do not skip the pre-mix.
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Test your current TA level. Do not proceed without a baseline reading. You need to know how far below target you are to calculate the correct dose.
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Calculate your dose using the table above. If your pool volume is not listed, multiply your pool size (in thousands of gallons) by 1.5 lbs and divide by 10 to get the lbs needed per 10 ppm.
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Turn the pool pump ON. The pump must be running during and after the baking soda addition. Circulation distributes the chemical evenly.
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Fill a 5-gallon bucket one-third to one-half full with pool water. This is the CPO pre-mix procedure used by certified pool operators. The CPO chemical pre-mix procedure{:target=“_blank”} specifies filling the bucket with water first before adding the chemical.
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Add the measured baking soda to the bucket. Pour the chemical into the water, not the other way around. This prevents clumping on the pool floor and allows proper dissolution.
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Stir until dissolved. Baking soda dissolves quickly in warm water, usually within 30-60 seconds of stirring.
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Pour the dissolved solution slowly around the pool perimeter, walking as you pour. Alternatively, pour near the return fittings to aid even distribution. Do not dump it all in one spot.
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Run the pump for 6-8 hours minimum before retesting. Do not retest immediately. Chemistry readings stabilize over several hours as the chemical fully distributes.
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Retest TA after 6-8 hours. If still below target, calculate the additional dose needed and repeat the process the following day. Do not add two large doses within the same day.
Important: Do not add baking soda and muriatic acid at the same time or within the same session. Add one chemical, allow it to fully circulate and register, then evaluate whether further adjustments are needed.
According to EPA pool chemical safety guidance{:target=“_blank”}, always store pool chemicals separately and follow label directions for handling.
What to Expect After Adding Baking Soda
Here is what we expect after a successful baking soda addition:
TA rises over 6-8 hours. The reading you get immediately after adding is not accurate. Give the pool pump time to distribute the chemical before retesting.
Slight cloudiness for up to 24 hours is normal if you added a large dose (over 20 ppm). The water is experiencing mild calcium carbonate precipitation. It clears on its own. Run the pump continuously.
pH should stabilize. This is the main benefit you will feel. After TA is in range, pH stops bouncing. You may still need to adjust pH, but it will hold after adjustment rather than drifting back immediately.
After TA is corrected, adjust pH if needed. If pH is still too high, use muriatic acid for pool pH to lower it carefully. If pH is low, use soda ash. Always adjust TA before pH. This is the sequence that matters.
After verifying your chemistry is balanced, run a pool shock treatment guide if you have been dealing with persistent cloudiness or any signs of algae during the imbalance period.
Troubleshooting: why isn’t my alkalinity going up?
Problem: Added baking soda but TA did not rise enough.
Check these first:
- Did you wait 8+ hours before retesting? TA takes time to register. Testing too soon produces a low reading that improves on its own.
- Did you measure accurately? Eyeballing baking soda volume with a measuring cup produces inconsistent results. A kitchen scale gives you the right amount.
- Is pool water evaporating rapidly? High summer evaporation can concentrate your pool and change readings in ways that mask the increase. Measure pool volume accurately.
Problem: TA went up but pH is still crashing.
pH stabilizes naturally once TA reaches 80+ ppm. Wait 24 hours after the TA correction before drawing conclusions about pH stability. If pH is still bouncing at 80 ppm TA, check whether you have aeration equipment (waterfall, fountain, jets) that is constantly off-gassing CO2 and raising pH. That is a different problem from low TA.
If a green pool problem emerged during the chemistry imbalance, our green pool water fix guide covers the SLAM process for clearing algae once chemistry is back in range.
Problem: Water turned cloudy after adding baking soda.
You added too much in a single session (more than 30 ppm). Calcium carbonate is precipitating. Run the pump 24-48 hours continuously. Run the filter. The cloudiness clears on its own. A clarifier can speed up the process if needed. Next time, raise TA in smaller increments with at least 24 hours between additions.
For hot tub owners with the same issue, the hot tub alkalinity guide covers the equivalent spa procedure.
FAQ
How long does baking soda take to raise pool alkalinity?
Baking soda begins working immediately, but the reading stabilizes after 6-8 hours as the chemical distributes through the pool. Retest at the 6-8 hour mark for an accurate reading. Do not rely on a test taken within 30-60 minutes of addition.
Can I use grocery store baking soda instead of pool alkalinity increaser?
Yes. Grocery store baking soda and pool store “alkalinity increaser” are both sodium bicarbonate. The chemical is identical. Pool store versions cost 3-5x more per pound with no difference in effectiveness. Buy baking soda in bulk from a grocery or warehouse store.
How many pounds of baking soda does it take to raise alkalinity by 10 ppm?
1.5 lbs of baking soda per 10,000 gallons raises Total Alkalinity by approximately 10 ppm. For a 15,000-gallon pool, you need 2.25 lbs per 10 ppm increase. For a 20,000-gallon pool, 3 lbs per 10 ppm increase.
Will baking soda raise my pool pH as well?
Slightly, yes. Baking soda (sodium bicarbonate) has a pH of around 8.3, so large additions can nudge pool pH upward. The effect is modest compared to soda ash (sodium carbonate). If pH rises after baking soda addition, wait until the TA stabilizes, then test pH separately and adjust if needed.
What if I add too much baking soda?
Excess baking soda causes two things: temporary cloudy water from calcium carbonate precipitation, and TA that is higher than your target. The cloudiness clears within 24-48 hours of continuous pump operation. If TA is now too high, you will need to lower it with muriatic acid. Add acid carefully in small doses, test frequently, and remember that acid also lowers pH, so balance both together.