Baking Soda Pool Calculator
Calculate exactly how much baking soda to add to your pool to raise alkalinity to the ideal range.
Baking Soda Needed
Sodium Bicarbonate (Baking Soda)
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How to Add Baking Soda to Your Pool
- Turn on your pool pump to ensure circulation.
- Broadcast the baking soda across the pool surface — don't dump it in one spot.
- Let the pump run for at least 1 hour to fully dissolve and distribute.
- Wait 6 hours, then retest your alkalinity.
- If still low, repeat with a smaller dose.
You can swim about 30 minutes after adding baking soda. Wait 6 hours before retesting for an accurate reading.
Baking Soda Quick Reference
How much baking soda to add for common pool sizes (to raise alkalinity by 10 ppm):
| Pool Size | +10 ppm | +20 ppm | +30 ppm |
|---|---|---|---|
| 5,000 gal | 0.75 lbs | 1.5 lbs | 2.25 lbs |
| 10,000 gal | 1.5 lbs | 3.0 lbs | 4.5 lbs |
| 15,000 gal | 2.25 lbs | 4.5 lbs | 6.75 lbs |
| 20,000 gal | 3.0 lbs | 6.0 lbs | 9.0 lbs |
| 25,000 gal | 3.75 lbs | 7.5 lbs | 11.25 lbs |
How Much Baking Soda to Add to a Pool
Baking soda (sodium bicarbonate) is the most common and affordable way to raise your pool's total alkalinity. It's the same product sold as "alkalinity increaser" at pool stores — just at a fraction of the price. A standard box of Arm & Hammer from the grocery store works identically.
The Baking Soda Formula
The dosing formula for baking soda in pools is:
lbs of baking soda = (Pool Gallons × PPM Increase) ÷ 10,000 × 1.5
Rule of thumb: 1.5 pounds of baking soda raises 10,000 gallons by about 10 ppm. For a typical 15,000-gallon pool that needs a 20 ppm boost, that's roughly 4.5 pounds — about 4 to 5 standard boxes.
When to Add Baking Soda to Your Pool
- Alkalinity below 80 ppm — your pH will be unstable and bounce around, making it hard to balance other chemicals.
- After heavy rain — rainwater is acidic and dilutes alkalinity.
- After draining and refilling — fresh water typically has low alkalinity.
- pH keeps dropping — low alkalinity is usually the root cause of pH instability.
Baking Soda vs. Pool Store Alkalinity Increaser
They're the same chemical: sodium bicarbonate (NaHCO₃). The pool-branded version typically costs 3–5x more per pound. Any baking soda with "sodium bicarbonate" as the only ingredient will work. Arm & Hammer is the most popular choice among pool owners.
Tips for Adding Baking Soda
- Always adjust alkalinity before adjusting pH — alkalinity changes affect pH, but not the reverse.
- Don't add more than 2.5 lbs per 10,000 gallons at once. Make large adjustments in stages.
- Broadcast it across the pool surface with the pump running for even distribution.
- Retest after 6 hours — it takes time for baking soda to fully dissolve and circulate.
- Baking soda will raise pH slightly as well. If your pH is already high, consider using soda ash alternatives or adjust in smaller doses.
Frequently Asked Questions
How much baking soda do I add to my pool?
Use the calculator above for an exact amount. As a rule of thumb, add 1.5 pounds of baking soda per 10,000 gallons of water to raise alkalinity by 10 ppm.
Can I use regular baking soda from the grocery store?
Yes. Grocery-store baking soda is chemically identical to pool-branded alkalinity increasers. Any brand with "sodium bicarbonate" as the only ingredient works perfectly.
How long after adding baking soda can I swim?
You can swim about 30 minutes after adding baking soda, once it has fully dissolved. Wait at least 6 hours before retesting your alkalinity for an accurate reading.
Will baking soda raise my pool's pH?
Slightly, yes. Baking soda has a pH of about 8.3, so it nudges pH upward. If you only need to raise pH without affecting alkalinity much, use soda ash (sodium carbonate) instead.
How much baking soda is too much?
Don't add more than 2.5 lbs per 10,000 gallons at once. Over-dosing can spike your pH and cloud the water. Make large adjustments in stages, retesting between doses.
Need to lower alkalinity instead? Use our full alkalinity calculator which covers both raising and lowering with acid.