How Do You Balance Pool pH?
Your pool should be a refreshing place to cool off in the heat, splash around with family and friends or get some aquatic exercise. When your pool’s pH is off-balance, however, the water could be less pleasant to be in and could have a negative effect on your pool equipment.
You may have learned about pH in chemistry class — the scale ranges from 0 to 14 and is used to measure how acidic or basic an aqueous solution is. When you’re testing with test strips and treating pool water, pH is one of the most important aspects of your water to understand and keep in balance.
What Is Balancing a Pool?
You probably already know that keeping pool water sanitized is important. Swimmers, debris, bugs and anything else that finds its way into your pool can leave behind germs that compromise your pool water’s safety and quality. But did you know these things can also throw off the balance of your pool water’s chemistry?
Keeping the water properly balanced is about maintaining certain chemical measurements in the pool water within healthy ranges. There are three key measurements to pay attention to when you’re balancing pool water:
- pH: Experts generally recommend the pool pH level of your water is between a reading of 7.3 and 7.6. This range is slightly above a neutral pH of 7, meaning it is slightly more alkaline, or basic, than acidic. Achieving the right pH level is key since you can experience problems when water is too far to either end of the pH scale.
- Total alkalinity: Total alkalinity is the amount, expressed as parts per million (ppm), of all alkaline substances in your swimming pool. Your pool water’s alkalinity will determine how well it can resist changes in pH. In other words, the right amount of alkalinity keeps the water’s pH from fluctuating dramatically. For most pools, total alkalinity should be in the range of 80 ppm to 120 ppm.
- Calcium hardness: Calcium hardness is your swimming pool's ratio of dissolved calcium to water. Higher levels of calcium, along with minerals like magnesium, cause water to become “hard,” while low levels leave water “soft.” The proper level of calcium hardness in pool water should be in the range of 200 ppm to 400 ppm.
In addition to understanding these different measurements, you should understand in what order you balance pool chemicals. Start with total alkalinity since this will have an effect on pH. Then, test and adjust pH levels if needed. Finally, you can adjust calcium hardness if it is out of range. Finish by sanitizing the pool and adding any other substances the pool needs.
Why Keeping a Balanced Pool Is Important
Keeping your pool water well balanced is essential for allowing your sanitizer to work, keeping your pool in good working order and keeping the water comfortable for swimmers.
To understand the problems that come when water is out of balance, we need to understand the way water attempts to achieve balance on its own. When water is under-saturated or over-saturated, it will either strip the surfaces it contacts or deposit scale to get closer to a neutral level of saturation.
1. Under-Saturated Water Problems
When water is too acidic and too soft, it is under-saturated and is corrosive or aggressive. In other words, this water will attempt to dissolve any minerals it comes into contact with. These corrosive effects can damage pool equipment and materials, such as your filtration system, heating system, pump, tile, grout and plastic.
Acidic water can also irritate swimmers’ skin and eyes. Since acidic water dissolves oils on the body, your skin may feel itchy, you may develop a rash, your eyes may burn and your hair may feel dry. These are all unpleasant effects you don’t want to experience when you go for a swim.
2. Over-Saturated Water Problems
Water that is too basic or too hard can also cause problems. This water has undissolved minerals in it, making it over-saturated. Pool water that is full of undissolved minerals will look cloudy, and the water will deposit minerals in the form of scale on plumbing equipment and other objects in the pool. Scale may look like crystal deposits or a hazy film over surfaces. Over time, scale can cause serious problems for your pool’s functionality.
Pool water with a high pH will also inhibit your chlorine’s ability to kill germs. Chlorine works by combining with water to form hypochlorous acid. This weak acid breaks down bacteria to sanitize your pool. Water that is too basic won’t allow hypochlorous acid to form as it should. Instead, as you add chlorine to your pool water, it will primarily form hypochlorite, which isn’t able to kill pathogens nearly as effectively as hypochlorous acid.
3. Fluctuating pH Problems
Since a pH that is either too acidic or too basic can cause problems, it’s important to maintain the right level of total alkalinity so your pH level remains stable within the proper range. You don’t want your pool water to be too acidic one week and too alkaline the next. Testing your pool water regularly and keeping all the relevant levels within their proper ranges is key to maintaining a safe, comfortable and long-lasting pool.
How to Balance Pool pH
As we’ve seen, balancing your pool’s pH is crucial if you want to make your pool water safe and comfortable and keep your pool in great shape. So, what do you do if your pool’s pH is out of the proper neutral range? Fortunately, you can alter pH levels by adding certain chemicals to achieve balance. Let’s look at how to balance pool water, whether its pH is too low or too high.
Raising Pool pH
When pH is too low, you need to add chemicals that are naturally alkaline to the water. These chemicals will dissolve into the water and raise the overall pH of the water. The two main chemicals used for raising pool-water pH are sodium bicarbonate and sodium carbonate. While they serve a similar purpose, there are occasions where one may be a better choice over the other:
- Sodium bicarbonate: More commonly known as baking soda, sodium bicarbonate is mildly alkaline. This substance works well when you only need to raise your water’s pH slightly. Sodium bicarbonate will have a more noticeable effect on the water’s total alkalinity, so if both pH and total alkalinity are low, sodium bicarbonate may be a better choice than sodium carbonate. However, if your pool water is well below 7.2, you would need to add a large amount of sodium bicarbonate to make up the difference.
- Sodium carbonate: Sodium carbonate is also called soda ash. This chemical is far more alkaline than baking soda, making it more effective at raising the pH of water that’s too low. Soda ash will also have an impact on total alkalinity. Some pool owners may prefer baking soda because it doesn’t cloud the water as much. However, it doesn’t take as much soda ash to get the job done. Typically, it takes about 6 ounces per 10,000 gallons of water to add 0.2 to the pH level.
These chemicals both come in powder form. You can purchase them in large bags from pool supply stores. You should measure out the amount you need and then sprinkle the powder onto the surface of the water, away from the skimmer so it won’t immediately enter the pool’s circulation system. The powder should dissolve right away, leaving your water less acidic.
Lowering Pool pH
What if your pool water’s pH is too high? In this scenario, you need to add an acid to bring the pool water back down to a neutral pH. The most common acids pool owners and pool care professionals use to lower pH are muriatic acid and sodium bisulfate. The main difference between these acids is the form they come in:
- Muriatic acid: Muriatic acid, also known as hydrochloric acid, is a powerful corrosive that comes in liquid form. Because working with an acid can be dangerous, you should wear protective eye goggles and gloves when you pour muriatic acid into your pool. You can either turn off the pool’s pump and pour the acid into the deepest part of the pool before turning the pump back on, or you can pour it over the return jets.
- Sodium bisulfate: Sodium bisulfate is also sometimes referred to as dry acid. It usually comes in granular form. As with muriatic acid, you should exercise care while working with sodium bisulfate. However, dry acid is generally safer to work with than muriatic acid. Sprinkling the powder over the return jet site will allow it to spread effectively throughout the pool.
You should be able to find these acids in pool supply stores. Whenever you’re working with an acid, carefully follow the instructions and prioritize safety. While sodium bisulfate is safer than muriatic acid, you should still exercise caution by keeping the container close to the water’s surface while you sprinkle it into the pool and keeping the acid downwind from you to prevent any granules from blowing onto you.
Maintaining and Monitoring pH on an Ongoing Basis
In order to keep your pool’s pH within a healthy range, you need to know when it goes out of range. Accordingly, you should check your pool’s pH level frequently.
Residential pool owners should check their pH and chlorine levels daily as part of their swimming pool maintenance, before the first swim of the day. During hot weather or heavy use, you may even want to check the pH twice per day. In public swimming pools, the Centers for Disease Control and Prevention (CDC) recommends pool staff check the pH and disinfectant levels at least twice per day and as often as hourly during periods of heavy use.
Even if you’re not using your pool as frequently, you should conduct tests on an uncovered pool after it rains since rainwater can have an acidic effect. You should also test your pool after adding chemicals. Wait the recommended length of time for the chemical to take full effect. Then test the water to see if you’ve achieved the right balance or need to treat the water further.
Testing Pool pH
Testing is necessary for keeping a pool in balance. There are a few different ways you can conduct these tests:
- Manual test strips: One of the most rudimentary ways of testing pH is by using testing strips. You insert one of these strips at least a forearm’s depth into the water, then pull it out, shake off excess water and watch as the strip changes color. Then, you compare the color on the strip to a key on the test packaging, which displays different hues along with the pH level they indicate.
- Manual droplet tests: Another type of manual test involves filling a vial with pool water that is taken below the water’s surface. Then, you add drops of phenol to the water and watch for the water to change colors. Like with the testing strips, you can compare the color to a key to determine the water’s pH level. You can also perform the same style test with different droplets to test chlorine levels.
- Smart pH monitors: The easiest and most accurate tests are automatic pool pH testers. These high-tech options remove the guesswork and allow you to test pH effortlessly. The SENSE device from WaterGuru connects to an app on your phone, so you can remotely test pH levels any time you need to. SENSE also tests chlorine levels, temperature and flow.
Testing Total Alkalinity and Calcium Hardness
Since total alkalinity and calcium hardness are also important parts of keeping your pool well-balanced, you should also test these levels periodically. An in-depth test of all your pool’s chemical levels isn’t something you need to do daily, but you should make it an occasional part of your pool care routine.
WaterGuru customers have access to our lab-grade pool water quality analysis, called TEST. This more in-depth test involves sending in a sample of your pool water. You’ll receive a custom report with your pool’s data and our recommendations for balancing your pool sent straight to your mobile app. These results include your pool’s total alkalinity and calcium hardness. Additionally, TEST will give you readings on your pool’s cyanuric acid, copper, iron, salt and phosphate levels.
Simplify Pool Care With WaterGuru SENSE
When you want to test your pool’s pH levels and other important metrics in a way that’s more convenient and accurate than manual tests, WaterGuru has the ideal water testing solution in our SENSE Smart Testing Kit. This system includes a lab-grade test and the SENSE device to help you monitor your pool’s pH and chlorine levels daily and on demand.
SENSE fits right into your pool skimmer opening, so you can get a true measure of your pool water rather than testing the surface water. It installs in seconds, and the mobile app makes it especially convenient to check your pool’s balance any time and anywhere. Purchase WaterGuru SENSE today to enhance your testing abilities so you can keep your pool water well balanced.