Alkalinity is a measure of how well your pool water can resist changes in pH. It acts as a buffer that keeps the pH level stable and prevents it from becoming too acidic or too alkaline. Alkalinity is important for maintaining the health and comfort of swimmers, as well as the performance and longevity of your pool equipment and surfaces.
What is the Ideal Alkalinity Range for Pool Water?
The ideal alkalinity range for pool water is between 80 and 120 parts per million (ppm). This range may vary slightly depending on the type of sanitizer you use, such as chlorine, bromine, or salt. You can check the alkalinity level of your pool water using a water testing kit or a digital tester.
How to Increase Low Alkalinity in Pool Water
If your pool water has low alkalinity, below 80 ppm, it means that it is too acidic and can cause corrosion, staining, cloudy water, and eye and skin irritation. To increase the alkalinity level, you need to add an alkalinity increaser, such as sodium bicarbonate (baking soda) or sodium carbonate (soda ash).
The amount of alkalinity increaser you need to add depends on the size of your pool and how much you want to raise the alkalinity level. You can use a pool calculator to determine the exact dosage. As a general rule, you can add up to 25 pounds of sodium bicarbonate per 10,000 gallons of pool water to raise the alkalinity by 10 ppm.
To add the alkalinity increaser, follow these steps:
- Turn off the pool pump and filter system.
- Wear gloves and eye protection to avoid contact with the chemical.
- Sprinkle the alkalinity increaser evenly over the deep end of the pool.
- Wait for two hours to let the chemical dissolve in the water.
- Turn on the pool pump and filter system and run it for at least eight hours.
- Test the alkalinity level again and repeat the process if needed.
How to Decrease High Alkalinity in Pool Water
If your pool water has high alkalinity, above 120 ppm, it means that it is too alkaline and can cause scaling, cloudy water, reduced chlorine effectiveness, and eye and skin irritation. To decrease the alkalinity level, you need to add an acid, such as muriatic acid or sodium bisulfate (dry acid).
The amount of acid you need to add depends on the size of your pool and how much you want to lower the alkalinity level. You can use a pool calculator to determine the exact dosage. As a general rule, you can add one quart of muriatic acid per 10,000 gallons of pool water to lower the alkalinity by 10 ppm.
To add the acid, follow these steps:
- Turn on the pool pump and filter system.
- Wear gloves and eye protection to avoid contact with the chemical.
- Dilute the acid with water in a plastic bucket according to the product label instructions.
- Pour the acid solution slowly along the edge of the pool, away from any metal parts or fittings.
- Wait for at least four hours to let the chemical mix in the water.
- Test the alkalinity level again and repeat the process if needed.
How to Maintain Balanced Alkalinity in Pool Water
Once you have balanced the alkalinity level in your pool water, you need to maintain it by testing it regularly and adjusting it as needed. You should test your pool water at least once a week during peak season and once a month during off-season. You should also test your pool water after heavy rain, high bather load, or adding any chemicals.
To keep your pool water balanced, you should also monitor and adjust other factors that affect alkalinity, such as pH, calcium hardness, temperature, and sanitizer levels. You should also use a metal sequestrant or stain remover to prevent metal stains from unbalanced water. By following these tips, you can enjoy clear and comfortable pool water all year round.