In the first in our water balance series, we offer a brand-new video talking about everything you need to know about your swimming pool's pH. If you'd rather read through the article though, it is available below the video as well. 

Understanding the pH Scale

The pH scale measures how acidic or basic a substance is, ranging from 0 to 14. pH specifically measures the concentration of hydrogen ions in the water, which directly affects water chemistry and overall pool health. A pH value of 7 is considered neutral, while values below 7 indicate acidity and values above 7 indicate a more basic (or alkaline) environment. Know this scale and maintaining the proper, balanced pH in a swimming pool is essential for balanced water chemistry, water quality, swimmer comfort, and the effectiveness of pool chemicals.

Maintaining balanced water chemistry is essential for a safe and enjoyable swimming experience.

Acceptable Ranges for Swimming Pool pH

Swimming pool water should have a pH level between 7.2 and 7.8 (the recommended range for a pool's pH). This range ensures the water remains safe for swimmers while allowing chlorine and other sanitizers to function effectively. Water outside of this range can lead to various issues, including skin irritation, equipment damage, and compromised sanitation.

If your swimming pool’s pH is out of this recommended range, Pool Training Academy recommends you close the pool and adjust the pH until it is within these ranges again. It is important to regularly test your pool's pH using test strips, test kits, or meters to ensure it stays within the recommended range.

Ideal pH Range for Swimming Pools

To maintain your pool's pH level within the ideal range, remember that although the acceptable range is 7.2 to 7.8, the target pH range is 7.4 to 7.6. This narrower range optimizes chlorine efficiency while ensuring comfort for swimmers. It’s also important to note that a pH of 7.5 closely matches the natural pH of human tears, reducing eye irritation and making swimming more enjoyable.

Always use accurate testing methods, such as pH meters, to obtain reliable results when measuring your pool's pH.

Problems Caused by Low and High pH

There are a number of issues that can come from a pH level in your swimming pool that is out of balance:

Low pH (Below 7.2)

• Increased corrosion: Acidic water can corrode pool equipment, ladders, and pipes.

• Eye and skin irritation: Swimmers may experience stinging eyes and dry, itchy skin.

• Decreased chlorine effectiveness: Chlorine dissipates more quickly, leading to inadequate sanitation and potential bacterial growth.

• Damage to pool surfaces: Plaster, grout, and vinyl liners can deteriorate faster.

High pH (Above 7.8)

• Reduced chlorine efficiency: Alkaline water reduces chlorine's ability to kill bacteria and algae.

• Cloudy water: High pH can cause calcium and other minerals to precipitate, leading to murky water.

• Scale buildup: Excessive pH encourages the formation of scale on pool walls, plumbing, and filtration systems.

• Skin and eye irritation: High pH levels can cause discomfort for swimmers, similar to low pH levels.

Pool PH and Equipment

Maintaining the ideal pH level in your swimming pool is not just about swimmer comfort—it’s also essential for protecting your pool equipment and ensuring the longevity of your investment. The pH level of pool water is a direct measure of its acidity, and keeping it within the ideal range of 7.2 to 7.8 is crucial for both health and equipment maintenance.

When the pH in swimming pools drops too low, the water becomes acidic. This increased acidity can lead to eye irritation and skin discomfort for swimmers, but it also poses a serious threat to your pool equipment. Low pH can corrode metal components, damage pumps, heaters, and filters, and even degrade pool surfaces over time. Acidic water can also eat away at pool ladders, diving board bases, and other mechanical systems, leading to costly repairs or replacements.

On the other hand, if the pH level climbs too high, you may notice cloudy water and the formation of scale on pool walls and equipment. High pH can cause minerals to precipitate out of the water, leading to unsightly deposits and reduced efficiency of your pool’s mechanical systems. This scaling can block pipes, reduce water flow, and put extra strain on pumps and filters, ultimately shortening the lifespan of your pool equipment.

To keep your pool in top condition, it’s important to regularly measure and adjust the pH of your pool water. By maintaining the ideal pH level, you not only create a safer and more enjoyable swimming environment but also protect your pool equipment from unnecessary wear and tear. Regular testing and prompt adjustments are key steps in effective pool maintenance, helping you avoid issues like eye irritation, cloudy water, and equipment damage, and ensuring your pool remains a healthy place for swimmers all season long.

How to Adjust pH Levels

Adjusting your pH when it is out of balance is critical to maintain proper pH levels, which keeps swimmers healthy and your pool’s environment safe for your surfaces as well as your equipment.

The main reasons for adjusting pH include protecting swimmer health, preventing equipment damage, and ensuring water clarity.

Other chemicals, such as chlorine and various pool treatments, can also affect the pH level in your pool and should be monitored regularly.

NOTE: The amount of chemical needed to adjust pH will depend on your pool size.

Raising pH

If the pH is too low, you can raise it by adding:

• Add sodium carbonate (soda ash): The most common way to raise pH levels in a pool. Soda ash causes a significant and rapid increase in pH compared to other chemicals.

• Sodium Hydroxide: This is a liquid pH increaser that is used for automated dosing systems mainly.

• Oxygen: You can inject oxygen into your water to raise your pH as well.

NOTE: Raising pH with these chemicals can also slightly affect total alkalinity, so both pH and total alkalinity should be monitored and balanced for optimal pool water chemistry.

Lowering pH

If the pH in your swimming pool is too high, you can lower it by adding pH decreasers, which are chemical agents designed to reduce pH levels. Common pH decreasers include:

• Muriatic acid: A strong acid that quickly reduces pH and alkalinity.

• Sodium bisulfate (dry acid): A granular alternative to muriatic acid, often used in residential pools.

Always follow the manufacturer's instructions when using pH decreasers to ensure safe and effective pool water maintenance.

Does  Lowering pH Also Affect Alkalinity?

If using muriatic acid or sodium bisulfate to lower your pH, it will indeed affect your alkalinity levels in the pool as well. After making adjustments, use a test kit and a water sample to check both pH and alkalinity to ensure they are within the proper range. Testing the water regularly is important to maintain balanced pH and alkalinity levels. If those alkalinity levels are affected, simply raise them back up to acceptable ranges and you will get the best out of your pH once again.

How Do I Learn More About My Swimming Pool?

Knowing about the in's and outs of your swimming pool pH is only one of the many challenges pool and spa operators as well as homeowners face on a day to day basis. This article has given you a good, but brief understanding of a single aspect of professional swimming pool operation. Thankfully Pool Training Academy offers Certified Pool Operator® (CPO) Certification courses that will help you become the best aquatics operator you can be. To get signed up for a CPO Certification in your area, please follow this link: Click Here