Do you know the reason why lemon juice or certain soaps burn our eyes? It’s because our eyes are sensitive to substances that are too low or too high in pH. Similar to your eyes, it’s critical to make sure your swimming pool’s pH is in the ideal range.
When maintaining your swimming pool water, pH is the most important element in balancing water chemistry. But before you learn how to regulate your swimming pool’s pH, it is important to know what pH is and how it can affect the comfort, equipment, surfaces and sanitation of your swimming pool.
Maintaining the right pH balance is crucial for pool water quality. Our infographic shows how pH levels affect your pool and includes pH examples outside pool care.:
What is Pool pH?
In short, pH measures acidity. In pool chemistry, the pH scale shows how acidic or basic your water is. The scale ranges from 0 to 14, with 7 being neutral. For proper swimming pool pH, keep levels between 7.2 and 7.4. Water below 7 is acidic; above 7 is alkaline. Acidic substances like lemon juice and vinegar are low in pH, while alkaline substances like certain soaps are high. For example, the human eye’s ideal pH is around 7, which is why lemon juice or soap can irritate it.
Balancing your pool’s pH is crucial. Both high and low pH levels can cause pool equipment damage, poor water quality and skin irritation.
Pool pH Too High or Too Low? No pHroblem
It’s important to know that anything added to your pool water can influence pH levels. Your pool’s sanitation method is the greatest influencer. While the alternative Clear Comfort AOP pool sanitation is pH-neutral, chlorine can easily alter pH levels. Understanding the chemical characteristics of your primary sanitizer, whether a chlorine or salt water pool system, is crucial. This knowledge helps you choose the best pH chemicals for your pool.
Whether you’re building a new pool, renovating equipment or optimizing your current system, many options are available to regulate pH. Proper management ensures a balanced, safe swimming environment.
How to Lower Pool pH
If your pool’s chlorine levels are high, it can decrease your pool pH, resulting in acidic water. Pool water that’s acidic and has low pH can cause your pool surfaces to corrode and etch, which can hurt the value of your pool.
Acidic Sanitizers That Lower Pool pH
Pool sanitizers have pH levels that range anywhere from 2.8 to 14.0, so it’s critical to know how a sanitation method will impact your pool’s pH remediation system. Here are four primary sanitizers that will lower your pool’s pH:
- Gas chlorine: An extremely efficient sanitizer, but it can also be very dangerous if not handled carefully so there are fewer and fewer pools using it.
- Dichlor or Trichlor: Often known as chlorinated isocyanurates, dichlor and trichlor are solid chlorine compounds that are often used in residential pools and in hotels, motels and apartment complexes. Since trichlor and dichlor contain both chlorine and cyanuric acid, or CYA, they can raise your CYA levels over time. To learn more about CYA, please take a look at our blog post “Cyanuric Acid: Friend or Foe”. Additionally, in August 2020, Hurricane Laura struck the largest trichlor chemical plant, causing the current chlorine shortage and the expectation of trichlor prices increasing by 70 percent in a year.
- Bromine: A less common option as it is more expensive than chlorine and not as powerful of an oxidant, but it is occasionally found in hot tubs because it’s more stable in higher temperatures.
Did you know?
You can easily lower your chlorine use and keep your pool water balanced with pH-neutral Hydroxyl-Based AOP sanitation from Clear Comfort! The result is healthy, refreshing and crystal-clear pool water that’s always ready to enjoy.
How to Raise Pool pH
Have you ever noticed your hair turns green after swimming? It’s a common myth that chlorine causes this. In reality, it’s due to copper in the water from corroding pool equipment.
If your pool’s pH is too low or acidic, you can raise raise pH and alkalinity with basic chemicals like sodium bicarbonate or soda ash. Be aware that adding soda ash may temporarily cloud the water as calcium precipitates. Aerating the water with jets, fountains or waterfalls can also help raise the pH by removing carbonic acid.
Basic Sanitizers That Raise Pool pH
High pH can cause cloudy water and create scale, which is a crystalline buildup of inorganic materials, like calcium, that creates a white film around your pool’s water lines.
Higher pH can greatly diminish sanitizer and disinfectant performance in the water. It is important to understand that you get higher chlorine efficiency at a lower pH so it is advisable to operate on the low end of the range if your saturation index allows. For homeowners, the most common primary sanitizers that increase pH are:
- Sodium hypochlorite: Commonly known as liquid chlorine or bleach, sodium hypochlorite has a natural pH of around 13 and is rarely used on pools alone because it’s very unstable.
- Calcium hypochlorite: Calcium hypochlorite, or cal hypo, is both an oxidizer and sanitizer and is the most frequently used in the pool industry. With a pH around 11.8, depending on the concentration, cal hypo will require acid remediation to help lower the pH.
How to Lower Your Pool’s pH
If your pool’s pH is above the ideal 7.2 to 7.4 range, this means we must add something to bring that pH down. But does it really matter which chemical you choose to lower pH? Here’s some helpful information on today’s top three pH-lowering chemicals:
- Muriatic acid: Muriatic acid (HCI) is the most common pH lowering chemical, widely available and very effective but it is also the most hazardous to handle with both liquid and vapor forms being harmful to people and equipment. Muriatic acid also lowers alkalinity requiring remediation usually through manual additions of sodium bicarbonate.
- Sodium bisulfate: Sodium bisulfate (NaHSO4) is very similar to muriatic acid except that it is in a dry form either in granules or more recently in puck form designed for specific erosion feeders. Sodium bisulfate also lowers alkalinity, much like muriatic acid.
- Carbon dioxide: Another option for lowering pH is carbon dioxide or CO2. However, unlike the other two acids, CO2 will result in a gradual increase in alkalinity. One of the most efficient ways to balance pH and alkalinity is to set up a combo system of CO2 and either muriatic acid or sodium bisulfate and feed either in balanced unison or one at a time manually with a crossover switch. This can keep the alkalinity in the proper ranges without ever having to manually add chemicals to adjust the alkalinity.
How To Be Proactive With Pool pH
Knowing how to raise or lower pH is a great start for your pool’s pH system. However, you also need to understand the pH impacts from your water source. How can you adjust your pool’s pH if you don’t know the starting point? Water sources can vary significantly in pH levels and minerals. You’re doing yourself a disservice if you don’t understand the pH of your source water.
Choosing the right pool sanitation system saves you time, money, and headaches over pH balancing and maintenance. For an easy and healthy sanitizer, try Clear Comfort’s AOP pool treatment. It’s pH-neutral sanitation and the industry’s best practice. It boosts oxidation, minimizes chlorine and reduces the negative effects of imbalanced pH.
It’s important to understand that pool water with a pH level above the neutral 7.0 can still be corrosive if the water is not balanced within the Langelier Saturation Index, or LSI, proper ranges.
Maintaining proper pH balance for your swimming pool can be challenging, but it’s the most important part of balancing your pool water chemistry. Start your pH remediation system by minimizing pH-raising chlorine with AOP. Regularly test water chemistry and make minor adjustments. You’ll be ready to swim safe and happy with the best water quality.
Want a low-chlorine pool? Experience the comfort and convenience of Clear Comfort’s pH-neutral AOP pool and spa systems. Say goodbye to harsh chemicals and hello to balanced, healthy and refreshing water. Learn more now. »
Originally Published: Aug 17, 2021.

Zach Morris
VP of Customer Success