What Lowers pH in a Swimming Pool? Causes, Effects, and Solutions

Understanding the factors that contribute to low pH levels and how to address them

Introduction

Maintaining the proper pH balance in a swimming pool is crucial to ensure the water is safe and comfortable for swimmers, while also protecting the pool equipment from damage. The ideal pH level for a swimming pool is between 7.4 and 7.6, which is slightly alkaline. However, several factors can lower the pH level, making the water more acidic. In this article, we will discuss the causes of low pH in swimming pools, the effects of low pH, and how to address the issue.

Causes of Low pH in Swimming Pools

  1. Acidic Source Water

If the source water used to fill your pool is acidic, it can lower the pool’s pH level. This can be due to various factors, such as the presence of acidic minerals or industrial pollution in the water source.

  1. Rainwater


Rainwater is generally slightly acidic, with a pH level below 7. When it rains, the rainwater can dilute your pool water, lowering its pH level. The more rainwater that enters your pool, the more significant the pH drop.

  1. Organic Materials

Leaves, grass, and other organic debris that enter your pool can lower the pH level as they decompose. Additionally, swimmer waste, such as sweat and urine, can introduce organic acids to the pool, further reducing the pH.

  1. Chemical Additions

Using acidic pool chemicals, such as chlorine, muriatic acid, or sodium bisulfate, can lower the pool’s pH level. Overuse or improper dosing of these chemicals can cause a significant drop in pH.

Effects of Low pH in Swimming Pools

  1. Irritation to Swimmers

Low pH levels can cause eye and skin irritation for swimmers, making the water uncomfortable to swim in. Acidic water can also cause swimwear and pool accessories to fade or deteriorate faster.

  1. Damage to Pool Equipment and Surfaces

Acidic water can corrode metal pool equipment, such as ladders, pumps, and heaters, leading to costly repairs or replacements. It can also cause etching and damage to plaster, grout, and other pool surfaces.

  1. Reduced Effectiveness of Chlorine

Low pH levels can decrease the effectiveness of chlorine in your pool, as chlorine is less stable in acidic conditions. This can lead to problems with algae growth and water clarity.

How to Address Low pH in Swimming Pools

  1. Test and Adjust pH Regularly


Regularly test your pool water for pH, ideally at least once a week. If the pH level is below 7.4, use a pH increaser, such as soda ash (sodium carbonate), to raise the pH according to the manufacturer’s instructions. Be sure to follow the recommended dosing guidelines to avoid over-correction.

  1. Balance Other Water Chemistry Parameters

Maintaining proper alkalinity and calcium hardness levels can help stabilize your pool’s pH. Aim for a total alkalinity of 80-120 ppm and calcium hardness of 200-400 ppm.

  1. Remove Organic Debris

Regularly skim and vacuum your pool to remove leaves and other organic debris that can contribute to low pH levels. Using a pool cover when the pool is not in use can help keep debris out of the water.

  1. Monitor Chemical Usage

Be mindful of the chemicals you add to your pool and follow the manufacturer’s dosing guidelines. Use a pool calculator to determine the appropriate amount of chemicals needed for your pool’s size and water chemistry.

Conclusion

Understanding the causes of low pH in swimming pools and taking steps to address them can help ensure a safe and comfortable swimming environment while prolonging the life of your pool equipment and surfaces. By regularly testing and adjusting your pool’s pH levels, balancing other water chemistry parameters, removing organic debris, and monitoring chemical usage, you can maintain a healthy and enjoyable pool for years to come.

In addition, working with a reputable pool service company can help ensure that your pool remains in optimal condition, and they can provide expert guidance on maintaining proper water chemistry. By staying proactive and informed about your pool’s pH, you can enjoy the many benefits of a well-maintained swimming pool.