Keeping the pH of your swimming pool water balanced is crucial for maintaining a safe and comfortable swimming environment. The ideal pH range for pool water is between 7.2 and 7.8. If the pH rises above 7.8, the water becomes too alkaline, leading to several issues:
It's important to monitor pH regularly and know how to lower it when necessary. Here are the main options for reducing the pH of pool water:
The most common chemicals used for lowering pH are muriatic acid and sodium bisulfate. These acidic products are sold as pool pH reducers, pH minus, or pH decreasers.
Sodium bisulfate is a dry, granular chemical that dissolves easily in water. It is safer and less harsh than muriatic acid. Sodium bisulfate lowers pH and total alkalinity. Follow the dosage instructions on the package based on your pool's volume. Generally, use 1 pound of sodium bisulfate for every 10,000 gallons to lower the pH by 0.2. Pre-dissolve in a bucket of water before adding it directly to the pool.
Muriatic acid is a very strong acid, also known as hydrochloric acid. While it quickly and powerfully lowers pH, muriatic acid can be dangerous if handled improperly. Always add it to water rather than vice versa. First, dilute it in a bucket before slowly pouring it into the pool. Add about 1 quart of acid for every 10,000 gallons to reduce pH by 0.2. Never add it via the skimmer.
Running the pool pump and using fountains or water features will help remove carbon dioxide from the water, naturally increasing pH. This method avoids adding more chemicals. However, it takes much longer to see significant effects than using pH reducers.
If the pH is still too high after attempting other methods, drain 12–15% of the total water volume. Refill with fresh water, which will dilute the alkalinity. Make sure to retest and balance the chemicals after refilling.
While lowering pH is important for maintenance, prevention is ideal. Here are some tips:
Always exercise caution when handling and storing pool chemicals.
With routine testing and quick pH reduction when needed, you can maintain safe and comfortable swimming water for the whole season. Being prepared to lower the pH is essential for pool owners.
Use a pool test kit to check the pH level. If it is above 7.8, the water is too alkaline, and you'll need to lower it using the methods above. High pH causes cloudy water and reduced chlorine effectiveness, leading to algae growth, scale formation on surfaces, and irritation to swimmers.
The fastest method is to use a chemical pH reducer like muriatic acid or sodium bisulfate. These acidic products quickly lower pH and alkalinity. However, always handle chemicals with caution by wearing protective gear, working in a ventilated area, and adding them slowly to pool water rather than straight into the pool.
It's best to avoid household products, as they may contain impurities bad for pool water. Pool chemical pH reducers are formulated specifically for adjusting swimming pool alkalinity and pH to safe levels. Using vinegar or lemon juice can also lead to unbalanced chemistry later.
If your pH bounces back and forth between high and low, the main culprit is unstable total alkalinity levels. First, test and balance total alkalinity between 80 and 120 ppm. Then test and adjust the pH to between 7.2 and 7.8. Balancing both is key to avoiding pH fluctuations in pool water.
Test pH at least 2-3 times per week during the swimming season. Changes in pH can happen rapidly, so frequent testing lets you catch high or low levels before major issues occur. Ideal testing times are before adding chemicals or shocking the water, after heavy rain or use, and when first opening your pool for the season.
Keeping pH in check takes some work, but it's crucial for safe, clean, and comfortable pool water. Test pH often and use pool chemical reducers promptly when levels creep too high. With routine monitoring and adjustment, your pool will maintain proper balance.
Harry Virk is the director of CleaningPro Auckland. He has years of experience in the cleaning industry and his company is expert at providing exceptional cleaning services in Auckland. He has a passion for helping people and making sure that their homes are clean, tidy, and ready for visitors.