Maintaining Crystal-Clear Waters – A Comprehensive Guide to Lowering Alkalinity in Your Pool

how to lower alkalinity in pool


A pristine, inviting pool is a homeowner’s dream. However, achieving and maintaining the ideal pool water chemistry can be a challenging task. One critical aspect of pool water chemistry is alkalinity. High alkalinity levels can lead to issues like cloudy water and scaling. In this article, we will explore the importance of pool water alkalinity, the reasons it may rise, and provide a step-by-step guide on how to effectively lower alkalinity in your pool.

Understanding Alkalinity

Pool water alkalinity refers to its ability to resist pH changes. High alkalinity acts as a buffer, stabilizing the pH levels. While the ideal range for alkalinity is 80-120 parts per million (ppm), it can often increase due to various factors, including the use of alkaline chemicals, hard water, and debris. High alkalinity levels can lead to cloudiness and make it difficult to maintain an optimal pH, which should ideally be around 7.4 to 7.6. Here’s how you can lower alkalinity to achieve a balanced and sparkling pool.

Test the Water 

The first step in managing alkalinity is to test your pool water regularly using a reliable test kit. These kits will provide precise measurements of alkalinity levels. Ensure your pool is properly balanced by also testing for pH and chlorine levels. This information will help you determine whether you need to lower the alkalinity in your pool and how much adjustment is required.

Balance pH First

Before tackling alkalinity, it’s essential to ensure that your pool’s pH levels are within the ideal range. High pH levels often accompany high alkalinity. If your pH is too high, add an appropriate pH decreaseer to bring it down to the desired range of 7.4-7.6. This step is crucial because lowering alkalinity directly impacts pH, and you want to maintain a balanced environment for your pool.

Choose the Right Acid

To lower alkalinity effectively, you’ll need to use an acid. Muriatic acid and sodium bisulfate are the two primary options. Muriatic acid is potent and can quickly reduce alkalinity, but it requires careful handling and dilution. Sodium bisulfate, on the other hand, is milder and easier to work with. The choice between these two acids often depends on your comfort level with pool maintenance and the specific needs of your pool.

Calculate the Amount Needed

Before adding any acid to your pool, you must calculate the amount required to lower the alkalinity. This calculation depends on your pool’s size and the current alkalinity levels. Your test kit will provide information on how much acid you need to add to achieve the desired reduction in alkalinity.

Safety First

Safety is paramount when working with pool chemicals. Always wear appropriate protective gear, including goggles and gloves, and follow the manufacturer’s instructions for handling and diluting the chosen acid. It’s also crucial to add the acid gradually and directly into the pool, pouring it over a return jet to ensure even distribution.

Distribute the Acid 

Once you’ve prepared the acid solution, add it to your pool gradually. Pour the solution over the pool’s surface, near the return jet, and allow the pool pump to run for a few hours to circulate the water thoroughly. This will ensure the acid is evenly distributed and that it has time to mix with the pool water, reducing alkalinity throughout the pool.

Test and Repeat 

After allowing the acid to circulate, retest the pool water’s alkalinity to determine if it has reached the desired range. If the alkalinity is still too high, repeat the process, but be cautious not to add too much acid at once, as this can lead to rapid and excessive pH reduction.

Monitor and Adjust 

Maintaining proper pool water chemistry is an ongoing process. Regularly test your pool water for alkalinity, pH, and chlorine levels and make adjustments as necessary. Monitoring your pool’s alkalinity will help you maintain clear, balanced water that is safe for swimming.


Can you swim in a pool with high alkalinity?

A pH level of 7 means that water is neutral; above 7 means the water is alkaline, while below 7 indicates acidity. Aim for a pH level of between 7 and 7.6. If the water pH is higher than 8, anyone who swims in the pool is at risk of skin rashes, while a pH of lower than 7 can sting swimmers’ eyes.

What chemical will lower alkalinity in the pool?

The two most popular chemicals available to help you lower the total alkalinity in your swimming pool are muriatic acid and sodium bisulfate (also known as dry acid).


Lowering alkalinity in your pool is a critical step in maintaining a clean, inviting swimming environment. By following these steps, you can effectively manage and reduce alkalinity levels, ensuring that your pool water remains crystal clear and pH-balanced. Remember to prioritize safety and ongoing maintenance to enjoy your pool to the fullest. A well-maintained pool is not only visually appealing but also provides a safe and enjoyable space for family and friends to relax and have fun.

Read Also : Unravelling The Cosmic Mysteries – How to Make a Star in Little Alchemy 2