Balance Your Pool pH Like a Pro

What pH Balance Is and Why It Matters for Pool Maintenance  

The pH scale measures how acidic or alkaline your pool water is based on a range of 0 to 14. A pH of 7 is neutral, anything below 7.0 is acidic, and anything above 7.0 is alkaline. Because levels change constantly, you should test the pH of your swimming pool daily if possible, but at least 2-3 times per week, using a liquid test kit. 

For context, pure water has a pH of 7, but the pH of your pool will vary depending on the chemicals and minerals in your water. The water from your home’s tap that you fill up your pool with, for example, has a pH level range of 6.5-8.5 based on U.S. EPA requirements. But the pH levels of your pool change based on the weather, pool filtration systems, how hard your water is, how many people have used your pool, and other factors. When you add pool chemicals like chlorine to your pool to make it swim-safe, these also raise or lower your pool’s pH levels. 

Ultimately, the ideal pH range for swimming pool water is 7.4 to 7.6 with an acceptable range of 7.2 to 7.8. 

Chlorine, Alkalinity, and Other Factors Affecting Pool pH Levels

Chlorine is a crucial part of pool maintenance because it kills bacteria and algae, but its effectiveness depends on pH balance. If the pH is too high, for example, chlorine isn’t as effective and you’ll have to add more to hit 1-3 parts per million (ppm). 

Other factors impact pH balance too. Alkalinity, which acts as a buffer at the ideal range of 80-120 ppm, is incredibly important for stabilizing pH levels. Metals, pool chemicals, rain, debris, and minerals like calcium can shift pH over time too. This is why regular testing is vital for maintaining the right water chemistry and keeping your pool safe and clean.

Curious about how much chlorine to add to a pool? Read our complete guide.

How to Lower pH Levels in Your Pool

If levels rise above 7.8, here is how our experts recommend lowering the pH in your swimming pool: 

Chemical Methods

• Muriatic Acid: This strong acid effectively lowers pH but can be challenging to work with. Always dilute it before adding and pour it slowly around the pool while the pump is running.
• Sodium Bisulfate (Dry Acid): A safer, granular alternative, sodium bisulfate works gradually to decrease pH. Please follow package instructions for safe dosing.

Non-chemical Methods

• Aeration: Increasing water circulation through fountains, waterfalls, or air pumps helps naturally lower pH over time by releasing carbon dioxide (CO2). It’s important to note that the effect of aeration on pH is subtle, so it’s not a reliable method for big adjustments.
• Dilution: If the pH is high, partially draining and refilling the pool with fresh water can help restore balance.

If you want a more “natural” chemical approach, CO2  systems can be used to lower pH by infusing carbon dioxide into the pool water, forming carbonic acid and gradually lowering the pH.

How to Increase pH Levels in Your Pool

To bring your pool’s pH back up above 7.2, consider these options:

Chemical Methods

• Sodium Carbonate (Soda Ash): A common pH increaser, soda ash dissolves quickly and raises both pH and total alkalinity.
• Sodium Bicarbonate (Baking Soda): Although baking soda is mainly used to raise alkalinity, it can increase pH levels slowly as well.

Non-Chemical Methods

• Aeration: In the same way that aeration can lower high pH levels, it can also help increase pH levels over time. Just remember that it’s not effective for major adjustments.
• Dilution: If the pool water is too acidic, replacing some of it with fresh water that has a naturally higher pH can help stabilize it.

How To Adjust pH in a Pool Depending On Your Pool Type

The methods for increasing and decreasing pH levels apply to both in-ground and above-ground pools, but our pool experts want you to consider the following before making any decisions: 

• Above-ground Pools: Above-ground pools generally have less water, which means pH fluctuations can happen more rapidly, so test and adjust more frequently.
• In-ground Pools: In-ground pools are often larger and require more chemicals for adjustments but tend to have more stable pH levels.
• Outdoor Pools: Rain, leaves, and temperature shifts can affect the pH balance of outdoor pools. Rainwater, for example, is often slightly acidic and can lower pH levels.
• Indoor Pools: If your pool is inside, manage CO2 buildup — which can cause pH levels to rise — with proper ventilation and aeration.

Expert Tips for Maintaining Balanced Pool pH Levels

Here are a few additional guidelines for keeping your pool’s pH balanced. Remember: Regular maintenance and proactive adjustments will help you avoid costly repairs and maintain crystal-clear water all season long.

• Test frequently: Prevent imbalances before they become problematic by testing your water daily or at least 2-3 times per week. We recommend using a liquid test kit, which is more accurate than a test strip.
• Adjust incrementally: Whether raising or lowering pH in your swimming pool, add chemicals gradually to avoid overcorrection.
• Monitor alkalinity levels: Alkalinity acts as a buffer for pH stability and should stay between 80-120 ppm.
• Test and control phosphate levels: Regularly test for phosphates (which should be below 100 ppb) and use removers as needed to prevent algae growth.
• Check chlorine levels: If your chlorine isn’t performing as expected, check the pH before adding more chlorine.

Final Thoughts: Achieve pH Balance in Your Swimming Pool

Maintaining a perfect pH balance in your pool is essential for safe and comfortable swimming. Here is your three-step path to achieving the ideal pool pH:

1. Know Your pH: Get to know the pH scale and what affects it. Regularly test your water (2-3 times per week) with a reliable liquid testing kit to stay ahead of imbalances.
2. Adjust and Monitor: Stay proactive by regularly testing using a high-quality pool testing kit, making incremental adjustments, and monitoring alkalinity and chlorine levels.
3. Maintain and Clean: Let a robotic pool cleaner take care of the dirty work, keeping things clean and helping prevent pH swings caused by dirt and debris. 

With these steps, you’ll spend more time in the water and less time on pool maintenance. Not sure which robotic pool cleaner is right for you? Take our quiz to find out.