When your pool’s alkalinity drops below 80 ppm, the water becomes unstable. pH fluctuates wildly, chlorine loses effectiveness, and swimmers experience stinging eyes and itchy skin . Raising alkalinity is the fix—and it’s simpler than you think.
Using sodium bicarbonate (baking soda) is the most common and cost-effective way to increase alkalinity in pool water. Unlike soda ash, which dramatically raises both pH and alkalinity, baking soda primarily boosts alkalinity with only a slight effect on pH . That makes it the right tool for the job.
Why Alkalinity Matters for Your Pool
Total Alkalinity is the buffering capacity of your pool water—its ability to resist pH changes . Think of it as a shock absorber for your water chemistry.
When alkalinity is in the ideal range of 80–120 ppm, your pH stays stable, chlorine works efficiently, and your pool surfaces and equipment stay protected . Low alkalinity leads to:
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pH bounce: pH swings wildly, making balancing frustrating
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Corrosion: Metal parts like ladders, pumps, and heaters get damaged
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Swimmer discomfort: Stinging eyes and skin irritation from acidic water
How to Increase Alkalinity in Pool Water
The best way to increase alkalinity in pool water is with sodium bicarbonate—commonly known as baking soda. Arm & Hammer baking soda works just as well as commercial alkalinity increasers, often at a fraction of the cost .
Dosage rule: 1.5 pounds of baking soda per 10,000 gallons of water raises alkalinity by approximately 10 ppm .
Step-by-Step Process
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Test your water: Use test strips or a drop test kit. Write down your current total alkalinity and pH levels.
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Calculate your target: Determine how much you need to increase alkalinity in pool to reach the 80–120 ppm range.
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Measure the dose: For a 20,000-gallon pool needing a 10 ppm bump, you’d add about 3 pounds.
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Add the product: Sprinkle the baking soda directly into the pool in wide arcs to avoid clumping . Or dissolve it in a bucket of water first.
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Circulate the water: Run your pump for at least 4–6 hours to help it dissolve fully .
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Retest: Wait 6–24 hours, then test again. Repeat if needed.
Important: If your pH is already high (above 8.0), lower it first. Add acid to bring pH below 7.8, then add baking soda—otherwise, the bicarbonate may cloud the water .
Commercial Alkalinity Increasers
If you prefer prepackaged products, options like Leslie’s Alkalinity Up and HTH Alkalinity Up are 100% sodium bicarbonate and follow the same dosage guidelines . BioGuard Balance Pak 100 also raises total alkalinity with the same 1.5 lb per 10,000 gallon ratio .
Soda Ash vs. Baking Soda
Many pool owners confuse these two. Soda ash (sodium carbonate) raises both pH and alkalinity dramatically. Baking soda (sodium bicarbonate) raises alkalinity while only slightly increasing pH .
If both your pH and alkalinity are low, soda ash is the right choice. If only your alkalinity is low, baking soda is the correct solution to increase alkalinity in pool without overshooting pH .
Common Mistakes to Avoid
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Adding too much at once: Large additions should be divided into thirds and added every 6 hours . Overshooting can lead to scale formation and cloudy water .
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Not retesting: Always retest after 6–24 hours to confirm the adjustment .
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Skipping circulation: Turn on your pump and let it run to distribute the product evenly .
Conclusion
A regular increase alkalinity in pool routine keeps your water balanced, protects your equipment, and ensures comfortable swimming . Use 1.5 pounds of baking soda per 10,000 gallons to raise alkalinity by 10 ppm . [Internal Link: Compare pool maintenance products and costs]. [Internal Link: Learn more about protecting your pool equipment].
Test your water today. Balance your alkalinity and enjoy clear, safe water all season long.
