Signs of High pH in Pool

Pool pH will always fluctuate constantly, especially when you are dealing with so many variables as in a swimming pool. When it moves you will most likely find the pH of your pool drops to acid levels, especially in late summer when the load or usage is higher than the start of the season. But there will be times when the pH climbs on the scale and there will be signs of it. What are the signs of high pH in a pool?

Once the pH moves too high 7.8+ you’ll hear complaints about irritated skin, stinging eyes, dry skin, & sticky feelings from swimmers. You’ll notice that the H2O has become hazy/cloudy losing its appeal to those who use the pool, finally, test the pH of the pool H2O for a higher-than-normal result.

It will be a long summer if the reagents aren’t new and past their shelf life or you aren’t running the basic test you need to operate a swimming pool. Either way, Get on the Ball! or it will be a long hot summer.

Signs of High pH in Pool

High pH levels in a pool can manifest through several noticeable signs. Firstly, cloudy water or the formation of scale on pool surfaces, particularly around fixtures like jets and skimmers, may indicate elevated pH. Secondly, swimmers might experience skin and eye irritation, as high pH can affect the water’s ability to properly disinfect and sanitize.

Additionally, if the pH is too high, chlorine becomes less effective at killing bacteria and algae, leading to poor water quality and potential health hazards. Another sign is the reduced efficiency of other pool chemicals, such as algaecides and clarifiers, as their effectiveness diminishes in high pH conditions.

Lastly, high pH levels can also result in decreased equipment lifespan due to scale buildup in pipes and filters, necessitating costly repairs or replacements. Regular pH testing and maintenance are essential to prevent these issues and ensure a safe and enjoyable swimming experience.

pH measures the activity of free hydrogen and hydroxyl ions within a solution. While this is harder to figure out for the average person, that is why chemical testing strips have been created for the everyday pool owner. pH is testing the alkalinity and acidity in your swimming pool. Having your pH levels properly balanced ensures that the chemicals in your pool are at their optimum working range.

If your pool’s pH reading is too high there are more signs that you will start to notice. Irritated skin is a sign of a high pH level. Also, if you have too high of a pH level, it will start to affect the way chlorine cleans your swimming pool. You will start to notice it is not as clean as it once was.

If your swimming pool becomes cloudy this is a sure sign that the pH level in your swimming pool is too high. You need to address it right away. If your pH is not in the ideal range then your chlorine won’t protect the pool water from organic contaminants like algae that will slowly wait in the cracks and crevices of your pool for the chlorine residual to deplete and then they will spring into action populating your pool until it looks emerald green and in no time at all.

  • Proper pool pH is right in the middle of the spectrum the pH should be between 7.3 and 7.6 for optimum performance and the cleanest water. If you are testing regularly you should have seen some hints like the TA or total alkalinity starts to slide out of the ideal range of 80-120 ppm.
  • Alkalinity is the capacity of pool water to resist acidification. It should not be confused with which is a measurement on the pH scale.
  • Always remember pH is always after the fact.
  • If the pH gets higher than 7.8, the water becomes too alkaline.
  • When water is too alkaline, it reduces the effectiveness of chlorine the pool chemical that kills pathogens.
  • Water with a pH that’s too high also can cause skin rashes, cloudy water, and scaling on pool equipment.
  • Over time, scaling inside pipes can build up, restricting water flow and putting a strain on your pool circulation system that can lead to costly repairs.
What causes high pH in Pools?
  • Sudden rise in water temperature
  • Water features that take water out of the pool aerating it
  • Release of Carbon Dioxide(CO2)
  • Swimmers using sunblock or lotions
  • Liquid bleach, such as Clorox has a pH level of around 11-13
  • New pool surface and walls leaching in H2O
  •  Off-gassing  ………………………………………………………………………… Read more


Sources of High pH


High pH in a pool can stem from various sources, leading to imbalances that affect water quality and swimmer comfort. One primary source is the addition of alkaline substances to the pool water. Chlorine-based sanitizers, commonly used to disinfect pools, can raise pH levels as they break down and release hypochlorous acid. Additionally, calcium carbonate-based products like calcium hypochlorite, often used as shock treatments, can elevate pH levels. Another contributor is the presence of dissolved minerals, such as calcium and magnesium, in the fill water.

These minerals can increase alkalinity and raise pH when introduced into the pool. Environmental factors like rainfall can also influence pH levels, especially if the rainwater is acidic, causing a spike in alkalinity when it mixes with the pool water.

Furthermore, organic contaminants like sweat, urine, and sunscreen residues introduce nitrogen and ammonia compounds, which can increase pH as they decompose. Understanding these sources of high pH is essential for effectively managing water chemistry and maintaining a balanced pool environment. Regular testing, appropriate chemical dosing, and proper maintenance practices are key to controlling pH levels and ensuring optimal water quality for swimmers.

  • Algae can raise the pH this will happen at the start of a cloudy appearance
  • Adding strong liquid chlorine, calcium, or lithium hypochlorite chlorine could raise it.
  • Suddenly heating the water, whether from a pool heater or a string of sunny days, could up the pH.
  • Saltwater pools tend to be alkaline.
  • Adding fresh water from the hose may raise it, depending on the content of your tap water.
  • For a new pool, pebble or plaster finishes can raise the pH.
  • Time raises the pH in chlorinated pools. This happens naturally.

What are the signs of Low pH in a Pool?

  • Cause Chlorine By-Products(Chloramine)
  • Impact chlorine effectiveness
  • Eye irritation
  • Cause etching of plaster, grout, stone, concrete, & tiling in concrete pools.
  • Vinyl surfaces will also become brittle, risk of cracks & tares.
  • This can result in staining & cloudy pool H2O
  • Cause Irritated skin ………………………………………………………. Read more


Lowering pH in Pool


Lowering pH in a pool refers to the process of decreasing the pH level of the water to maintain proper balance and ensure swimmer comfort and safety. pH is a measure of the acidity or alkalinity of the water, with lower pH values indicating higher acidity. In a pool, the ideal pH range typically falls between 7.2 and 7.6.

Lowering the pH in a pool can be necessary if the pH level rises above the recommended range. This can happen due to various factors, including the addition of Chemicals: The use of certain pool chemicals, such as chlorine or bromine, can affect the pH level. Chlorine, for example, tends to raise the pH level over time.

Organic Matter: Organic contaminants such as sweat, urine, and debris from plants can contribute to pH fluctuations as they break down in the water.

Rainwater: Rainfall can introduce acidic elements into the pool, which can lower the pH.

To lower the pH in a pool, you can use pH decreaser or pH minus chemicals, which are usually acidic substances like sodium bisulfate or muriatic acid. It’s essential to follow the manufacturer’s instructions and wear appropriate protective gear when handling these chemicals. After adding the pH decrease, the pool water should be tested periodically until the desired pH level is reached. Additionally, maintaining proper pool circulation and filtration can help distribute the chemicals evenly throughout the water.

When you’ve tested and determined that your pool pH is too high, there are two ways you can adjust it:

  • Dry acid
  • Muriatic acid.

If you’re using a dry acid, use these steps:

  • Follow the manufacturer’s instructions on the package. Use the recommended dosage
  • You may be able to just add the dry acid directly or dissolve the chemical. 
  • Make sure the pool pump and filter pump are running.
  • Spread the product in the deepest part of your pool.
  • Use a pool brush to break up any clumps. This will also help disperse the dry acid evenly.

If using you’re using muriatic acid, use these steps:

  • If diluting-Never pour water into acid-pour Muriatic acid into water 
  • Read the package and follow the manufacturer’s instructions.
  • In some cases, you may need to mix and dilute the product.
  • Slowly pour the product into your pool. Take care to avoid spills and splashes where gloves and safety glasses.
  • Run the pool filter and pump unless the instructions say otherwise.
  • Apply the pH-balancing chemicals as detailed on the label.
  1. Testing pH Levels: Before attempting to lower the pH, it’s crucial to test the current pH level of the pool water using a reliable test kit. This will provide an accurate measurement of the acidity or alkalinity of the water and help determine the appropriate amount of pH decrease needed.
  2. Dosing Calculation: The amount of pH decrease required to lower the pH depends on the current pH level, the volume of water in the pool, and the specific product being used. Refer to the product’s instructions or use a dosing calculator to determine the correct dosage.
  3. Safety Precautions: When working with pool chemicals, always prioritize safety. Wear protective gear such as gloves and goggles to prevent skin and eye irritation. Handle chemicals in a well-ventilated area and avoid inhaling fumes. Keep the chemicals out of reach of children and pets.
  4. Application: A pH decrease is typically added directly to the pool water. Follow the manufacturer’s instructions for the recommended method of application. It’s essential to distribute the chemical evenly across the pool surface to ensure uniform pH adjustment.
  5. Wait and Retest: After adding the pH decrease, allow some time for the chemical to mix thoroughly with the pool water. Retest the pH level after a few hours to monitor the effectiveness of the treatment. If necessary, additional doses may be required to achieve the desired pH range.
  6. Balancing Other Parameters: Lowering the pH may also impact other water parameters, such as total alkalinity and calcium hardness. It’s essential to regularly test and adjust these parameters to maintain proper water balance and prevent issues such as corrosion or scale formation.
  7. Regular Maintenance: pH levels in a pool can fluctuate over time due to various factors, including bather load, environmental conditions, and chemical additions. Establishing a regular maintenance routine, including frequent pH testing and adjustment as needed, will help keep the water balanced and comfortable for swimmers.

By following these steps and practicing good pool maintenance habits, you can effectively lower the pH in your pool and ensure a safe and enjoyable swimming experience.


In conclusion, maintaining the pH level in a pool is essential for ensuring water quality, swimmer comfort, and equipment longevity. By regularly testing and adjusting pH levels within the recommended range of 7.2 to 7.6, pool owners can prevent issues such as cloudy water, scale formation, and skin irritation.
Understanding the factors that contribute to pH fluctuations, such as chemical additions, environmental influences, and organic contaminants, is crucial for effective pool maintenance.
With proper monitoring and timely adjustments using appropriate chemicals, pool owners can create a safe and enjoyable swimming environment for all users. Remember, consistent pH management is key to maximizing the lifespan of pool equipment and enhancing the overall swimming experience.

Why is My pH Always High in My Saltwater Pool?

The reason why saltwater pools usually have elevated pH levels is that the generation of chlorine with the electrolysis process tends to create byproducts like Sodium hydroxide, also known as lye and caustic soda that have a very high pH, Sodium Hydroxide has a 13 pH and is extremely high, or .…………………………………………….. Read more

JimGalloway Author/Editor


Atlas Scientific-What Causes High pH in Pools


How often should I test the pH level in my pool?  It’s recommended to test the pH level in your pool at least two to three times per week using a reliable test kit. However, factors such as bather load, weather conditions, and chemical additions may necessitate more frequent testing.

What causes pH levels to rise in a pool?  pH levels in a pool can rise due to various factors, including the addition of alkaline chemicals like chlorine and shock treatments, dissolved minerals in the filled water, environmental factors such as rainfall, and the accumulation of organic contaminants from swimmers.

How can I lower the pH in my pool?  To lower the pH in a pool, you can use pH decreaser or pH minus chemicals, such as sodium bisulfate or muriatic acid. It’s essential to follow the manufacturer’s instructions, wear protective gear, and test the water regularly until the desired pH range is achieved.

What are the consequences of high pH levels in a pool? High pH levels in a pool can lead to several issues, including cloudy water, scale formation on pool surfaces, skin and eye irritation in swimmers, reduced effectiveness of chlorine and other pool chemicals, and increased equipment wear and tear due to scale buildup in pipes and filters.

Can I use household vinegar to lower the pH in my pool? While household vinegar (acetic acid) can lower pH levels in a pool, it may not be as effective or practical as commercially available pH decreases. Additionally, using large quantities of vinegar can significantly increase the pool’s total dissolved solids (TDS) and may not provide consistent results. It’s generally recommended to use products specifically designed for pool water maintenance.

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