Alkalinity Balance in Pools: How to Maintain Proper Levels for Healthy Pool Water

Maintaining the right chemical balance in your pool is crucial to its overall health and the comfort of swimmers. One of the most important factors to manage is alkalinity. Total alkalinity (TA) acts as a buffer to stabilize pH levels in the pool water. When it is out of balance, it can cause pH levels to fluctuate, leading to a variety of issues, from irritating water to equipment damage. In this post, we’ll walk you through how to balance alkalinity in your pool, the ideal range to aim for, and how to make adjustments when necessary.

What Is Alkalinity, and Why Does It Matter?

Alkalinity refers to the ability of the pool water to neutralize acids. Essentially, it acts as a buffer to prevent sudden changes in pH. Without proper balance, your pool’s pH can shift drastically, either becoming too acidic (which can corrode surfaces and irritate swimmers) or too alkaline (which can lead to cloudy water and scaling).

The ideal range for a pool is typically between 80-120 ppm (parts per million). When your pool’s water is in this range, it helps keep the pH stable and makes it easier to maintain balanced water chemistry overall.

If it is too low or too high, it can lead to a variety of problems, including ineffective chlorine use, cloudy water, and poor swimmer comfort.

Step 1: Test the Alkalinity

Before adjusting your pool’s water balance, you need to test it to determine whether it’s within the ideal range. You can test alkalinity using:

1. Test Strips: These are quick and easy to use. Simply dip the strip into the pool water and compare the color to the provided chart.
2. Liquid Test Kits: These kits are more accurate and involve adding a few drops of liquid to a water sample. The color change will indicate your pool’s TA level.
3. Electronic Testers: For precise readings, an electronic tester can be used, though these are generally more expensive than the other options.

Testing your pool’s alkalinity regularly—ideally once a week—will help you stay on top of any fluctuations that may require adjustments.

Step 2: Determine If You Need to Raise or Lower

Once you’ve tested the water, the next step is determining whether your pool’s alkalinity needs to be raised or lowered.

• Low Alkalinity (below 80 ppm): When your pool’s alkalinity is too low, the pH is more likely to fluctuate and become unstable, leading to corrosive water that can damage pool equipment and irritate swimmers’ skin and eyes.
• High Alkalinity (above 120 ppm): If the alkalinity is too high, it can cause the pH to drift upwards, leading to scale buildup on pool surfaces, cloudy water, and reduced sanitizer effectiveness.

Step 3: Adjust Alkalinity Levels

Depending on whether your pool’s alkalinity is too low or too high, you’ll need to make the necessary adjustments.

How to Raise Alkalinity

To raise your pool’s TA, you’ll need to add a substance called sodium bicarbonate (also known as baking soda). This is the most common and safe method to increase alkalinity without drastically altering the pH.

• How to apply sodium bicarbonate:
  • Calculate the amount needed based on your pool’s size. Typically, 1.5 pounds of baking soda is needed to raise the alkalinity by 10 ppm in a 10,000-gallon pool.
  • Dissolve the required amount of sodium bicarbonate in a bucket of water, and then pour it into the pool evenly around the perimeter. It’s best to add the chemical slowly to avoid sudden spikes.
  • Run the pool’s pump and filtration system for several hours to ensure even distribution of the baking soda.

How to Lower Alkalinity

If the TA is too high, you’ll need to use an acid to reduce it. Muriatic acid or dry acid (sodium bisulfate) are commonly used for this purpose.

• How to apply acid:
  • Calculate the amount of acid needed based on your pool’s size. Generally, about 1 quart of muriatic acid per 10,000 gallons of water can lower TA by about 10 ppm.
  • Always add the acid to a bucket of water (never the other way around) and then pour it slowly into the pool. Be sure to add the acid near the deep end of the pool to prevent concentrated acid from damaging the surfaces.
  • Run the pool’s pump and filtration system for at least 4-6 hours after adding acid to ensure thorough mixing and proper distribution.

Tip: If you are lowering alkalinity, you’ll also want to monitor your pH levels. Adding acid will lower both the pH and the alkalinity, so you may need to adjust the pH afterward to bring it back to the ideal range (7.4-7.6).

Step 4: Allow Time for Chemicals to Mix

After adding the chemicals, it’s important to allow the pool’s filtration system to run for several hours to help mix and distribute the chemicals evenly throughout the water. Avoid swimming in the pool until the chemicals are fully circulated and the water is safe.

Step 5: Test the Alkalinity Again

After allowing enough time for the chemicals to circulate, retest your pool’s water balance to check if it’s within the ideal range (80-120 ppm). If it’s still not within range, you can add more chemicals as needed, but be sure to add them gradually to avoid overcorrecting.

Step 6: Maintain Consistent Alkalinity

Once you have achieved the right alkalinity, maintaining it will be easier. Regularly test your pool’s alkalinity and adjust it as needed, especially after heavy rains, chemical treatments, or if you notice pH fluctuations.

• Tip: If you’re experiencing frequent issues with fluctuating alkalinity, you may want to check for other factors that could be affecting your pool chemistry, such as high calcium hardness, poor circulation, or incorrect pool chemical use.

Conclusion

Balancing the alkalinity in your pool is essential to keeping the pH stable and ensuring that your pool water is safe and comfortable for swimmers. Regular testing and making gradual adjustments will help you maintain the perfect balance. Whether you need to raise or lower alkalinity, always follow safety guidelines when handling chemicals and be patient with the process. By keeping your alkalinity in check, you’ll help protect your pool equipment, prevent water chemistry issues, and keep your pool sparkling clean.

If you’re unsure or need assistance in balancing your pool’s alkalinity, don’t hesitate to visit us in-store a for a free professional water test! We can help you achieve the best water quality possible.