What Causes Low pH in Pools

The pH level is the measure of how acidic or alkaline the water is. On a scale ranging from zero (highly acidic) to fourteen (highly alkaline), the ideal pH of pool water is between 7.2 and 7.8. There are plenty of things that can lower the pH of your swimming pool. What Causes Low pH in Pools?

Causes Low pH in Pools:

  • Chlorine tablets with stabilizer (CYA)-2.9 pH
  • Rain 5–5.5 pH
  • Children’s urine 6.0 pH
  • Shampoos 4.5-6.0.pH
  • Beer 4.00–5.00.& Ales 3.00–6.00 pH
  • Coffee 4.85-5.1 pH & Soda 2.5 to 3.5 pH
  • Leaves that fall are below 6 pH
  • Skin products & Cleansers: pH 4.5–7. Toners: pH 5–7. Sunscreens: pH 5–7.5.

Although the common way for your swimming pool to decrease its pH is by chemicals or chemical loss many things enter the pool water besides people but they are most likely carried in by the same people who enter the pool that day

What Causes Low pH in Pools


The most common cause of a consistently low pH level in pools is using chlorine tablets or stabilized forms of chlorine. These have a very low pH level and depending on how much cyanuric acid is added decrease the pH.

A chlorine tablet has two side effects that most pool owners don’t realize: It has a pH of 2.9 but more importantly, it lowers Total Alkalinity (TA). It is 52% cyanuric acid or conditioner/stabilizer by weight and each one increases the cyanuric acid level (CYA) in your pool water.

CYA is acidic and it keeps on lowering pH the entire time it is dissolving. Metal Free is also somewhat acidic. The sequestrant slowly decays in the pool. That is why regular maintenance doses are required.


Reasons for Lower Pool Water pH


There are several reasons why the pH of water may decrease, resulting in lower acidity levels. One common cause is the introduction of acidic substances into the water, such as acid rain or runoff from decaying organic matter. Additionally, carbon dioxide dissolving into water forms carbonic acid, further lowering pH levels.

Biological processes, such as the respiration of aquatic organisms, can also produce acids that contribute to pH reduction. Finally, the addition of certain chemicals or fertilizers to water bodies can lead to acidification, impacting aquatic ecosystems and water quality. Regular monitoring and mitigation strategies are essential to address low pH levels and maintain the health of aquatic environments.

Changes in the pH of pool water can be caused by many factors but one of the most significant causes is the sanitizer used. Since sanitizer is the most frequently added chemical in pools, it can have a powerful impact on pH and overall water quality.

Of the sanitizers typically used in pools, chlorine is the most common. Chlorine comes in a variety of forms and varies widely in pH. For example, most tableted forms of chlorine have a very low pH and will tend to lower pH over time, while liquid chlorine is very high in pH and does the opposite while raising pH values.

Salt is also very alkaline and will require frequent additions of acid to maintain the proper pH and overall water balance.

Changes in pH due to sanitizers or other factors can be minimized and controlled by the proper maintenance of the next chemical factor, total alkalinity. Lowering a pool’s pH naturally can be done in four ways: installing a distilled water system to pump in water, cleaning your pool regularly, leaving it alone, and letting the pH level come down on its own as minerals build up, or installing a pool heater. 


Low pH Low Alkalinity in Pool: Raise pH In Swimming Pool Water


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Acidic rainfall, heavy leaf debris, and dirt/mulch blowing in the pool can also lower the pH level.

Natural rainwater has a pH of 5 – 5.5, so it is naturally acidic. A substantial amount of rainfall can alter the pH of pool water to become more acidic.

If it has been raining heavily and your pool is uncovered, the pool water may experience a drop in pH levels. This occurs because rainwater is slightly acidic, especially in areas where there are industries, and can alter the pool’s chemical balance.

The average urine sample for children tests at about 6.0, but typical urine pH may range from 4.5 to 8.0. The higher the number of kids in your pool the more chance some kids will pee in it and some grownup kids.

Shampoos formulated at low pH can help protect the hair’s cuticle layer and the scalp’s microbiome. That’s because low-pH shampoos have the same pH range for the hair and the scalp: running from 4.5 to 6.0. pH. Plus, pH values can vary depending on the product’s ingredients.

Not only are sodas extremely high in sugar content, but they also have an extremely low, or acidic, pH. Most sodas have a pH in the range of 2.5 to 3.5 on the pH scale. This work found the pH measurements for all coffee samples tested to be comparable, ranging between 4.85 to 5.13.

Beer is thus slightly acidic, with 100% barley malt lager beers having a pH in the range of 4.00–5.00. Ales vary a little more, typically pH 3.00–6.00. Most leaves are slightly acidic when they fall, with a pH below 6. Yeah, I’ve seen a few beers and soda go into the pool.


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
  • Use of Algaecides ………………………………………………………………….. Read more

pH of Skin Care Products List


The pH of skin care products is important because it can influence their effectiveness and compatibility with the skin. The skin’s natural pH is typically acidic, ranging from 4.5 to 5.5, which helps maintain its protective barrier function.

Skin care products with pH levels close to the skin’s natural pH are often better tolerated and less likely to cause irritation or disruptions to the skin barrier. Formulators may adjust the pH of products to optimize their performance and ensure they are gentle and suitable for different skin types. However, individual skin sensitivities and preferences may vary, so it’s essential to choose products that work well for your skin’s unique needs and pH balance.

Nexxus Therappe is an excellent and popular shampoo for dry, brittle hair, and for people who struggle with hair breakage due to its patented ProteinFusion formula is 4.2-6.0 pH The pool’s pH levels might also drop after hosting a large pool party.

Dissolved bodily fluids can lower pH levels, so if you have had a lot of swimmers in your pool recently, this could be the culprit or maybe one or more of these multiplied by the number of people in your pool.

  • Cleansers: pH 4.5–7.
  • Toners: pH 5–7.
  • Sunscreens: pH 5–7.5.
  • AHA and BHA Exfoliants: pH 3.2–3.9, with any reading between 3 and 4 considered most effective.
  • Moisturizers: pH 5–7.
  • Serums: pH 4–6.
  • Vitamin C (ascorbic acid) products: pH 2.6–3.2.
  • Retinol products: pH 4–6.6

Pool Showers: Help Raise Lower pH in a Pool-Control Low Pool pH


You should always shower before going swimming. If you don’t, fecal matter and other nasty contaminants can easily start mixing into the pool water. Something that might surprise people is we all have small amounts of fecal matter on our bodies on most days. On average, the U.S. Center for Disease Control and Prevention estimates that people have 0.14 grams of fecal matter in their bodies.  So you might want to avoid swallowing pool water. It can make you very very sick.

Pool showers can inadvertently contribute to pH imbalance in a pool if they are not properly managed. Here’s how they can affect pH levels and some strategies to control low pool pH:

  1. Chlorine Wash-off: If pool users do not rinse off thoroughly before entering the pool, residual chlorine from their bodies can be washed into the pool water. Chlorine is acidic and can lower the pH of the pool water over time.
  2. Sweat and Body Oils: Pool showers help rinse off sweat and body oils, which can contribute to pH imbalance when introduced into the pool water. These contaminants can lower pH levels, especially if they are not properly managed.

To control low pool pH caused by pool showers:

  • Encourage Pre-swim Showers: Encourage pool users to take thorough pre-swim showers to rinse off sweat, body oils, and any residual chemicals on their bodies. This can help reduce the introduction of contaminants into the pool water and minimize the impact on pH levels.
  • Use pH Buffering Products: Consider using pH buffering products specifically designed for pools to help stabilize pH levels. These products can help prevent rapid fluctuations in pH caused by contaminants introduced through pool showers.
  • Regular pH Testing and Adjustment: Maintain a regular schedule for testing pH levels in the pool water and adjust pH as needed to keep it within the recommended range. This will help prevent pH imbalance and ensure a safe and comfortable swimming environment.
  • Monitor Pool Usage: Keep track of pool usage patterns and adjust maintenance practices accordingly. If pool showers are heavily used during peak times, consider increasing the frequency of pH testing and adjustment to maintain water balance.

By implementing these strategies and promoting responsible pool usage, you can help control low pool pH caused by pool showers and maintain optimal water quality for swimmers.

Swimmers showering can fight off a variety of Recreational Waterborne Illnesses(RWI). This prevents common causes of diarrhea, skin infections, and eye infections.

Using pool disinfectants like chlorine products protects us and prevents us from picking up waterborne germs. Organic compounds that mix with chlorine are found in deodorants, soaps, moisturizers, sweat, detergents, and fecal matter.

Recreational waterborne illnesses (RWIs)


RWIs are caused by pathogens that can be present in recreational water sources such as swimming pools, hot tubs, lakes, and rivers. Common RWIs include gastrointestinal illnesses, skin infections, and respiratory issues.

These illnesses can be contracted by swallowing, inhaling, or coming into contact with contaminated water. Prevention measures such as maintaining proper water quality, regular disinfection, and promoting good hygiene practices among swimmers are essential in reducing the risk of RWIs. Prompt detection and response to outbreaks of RWIs are also critical for mitigating their spread and protecting public health.


Raise Pool pH 


Pool pH should be raised when it falls below the recommended range of 7.2 to 7.6. It’s important to raise the pH if it consistently measures below 7.2 during regular testing. Additionally, if swimmers experience discomfort such as skin and eye irritation, or if pool equipment shows signs of corrosion, it may indicate low pH and necessitate raising the pH level. Regular pH testing and adjustment are essential to maintain optimal water balance and ensure a safe and enjoyable swimming experience.

When organic compounds are mixed with chlorine-treated water, by-products are created. These are gases called Chloramines. Chloramines lead to that unusual chlorine smell that we think is a sign of a clean pool. This is what causes low pH and low total alkalinity in a pool.

Low pH water and low alkalinity will cause irritated eyes and etching and deterioration of plaster, grout, stone, concrete, and tiling. Any vinyl surfaces will also become brittle, which increases the risk of cracks and tears. All of these dissolved minerals will hold in the solution of your pool water; which can result in staining and cloudy pool water.

To raise the pH level of a pool, follow these steps:

  1. Test pH Levels: Start by testing the pH level of the pool water using a pH test kit or strips. The ideal pH range for pool water is typically between 7.2 and 7.6.
  2. Calculate Adjustment Amount: Determine how much pH increaser (sodium carbonate or soda ash) is needed to raise the pH to the desired level. Follow the manufacturer’s instructions and use a pool calculator to calculate the correct dosage based on your pool’s size and current pH level.
  3. Broadcast pH Increaser: Add the calculated amount of pH increaser to the pool water. Broadcast the increaser evenly across the surface of the pool while the pump and filter system are running to help distribute it evenly.
  4. Allow Circulation: Allow the pool water to circulate for several hours to ensure thorough mixing and distribution of the pH increaser.
  5. Re-Test pH: After a few hours, re-test the pH level of the pool water to ensure it has reached the desired range. If necessary, repeat the process of adding a pH increaser until the pH level is within the recommended range.
  6. Monitor and Adjust: Regularly monitor the pH level of the pool water and make adjustments as needed to maintain it within the optimal range. Factors such as rainfall, bather load, and the use of pool chemicals can affect pH levels, so it’s essential to stay vigilant and proactive in pH management.

By following these steps and regularly monitoring pH levels, you can effectively raise the pH of your pool water to ensure optimal water balance and a comfortable swimming environment.

They’re not. The smell of chloramine are problem sign that the pool’s pH is not being maintained to the highest quality and the pH is inadequate. A well-managed pool should have little to no chlorine odor for environmental health and alkalinity pool pH problems.

The pool’s low acidic pool water can be adjusted with baking soda and soda ash baking soda aka sodium bicarbonate are two solutions you can add to the lower pool pH water to raise the pool’s pH.

You can add sodium carbonate or soda ash directly to the pool or spa to raise pH levels whatever the cause. For the best results, walk around the edge while you dump the chemicals to distribute them evenly. Add 1.5 pounds of baking soda per 10,000 gallons of water.

This pH problem makes a strong case for installing a pool shower at the swimming pool. Shower before you get into the water and Shower when you get out. Problem solved!



In conclusion, maintaining the proper pH level in a pool is essential for ensuring water quality, swimmer comfort, and the longevity of pool equipment. Low pH levels can lead to a range of issues, including skin and eye irritation, equipment damage, and chemical imbalance. By understanding the signs of low pH and taking proactive measures to address it, pool owners can create a safe and enjoyable swimming environment for all users. Regular testing, adjustment, and monitoring of pH levels are crucial components of effective pool maintenance. With diligence and attention to pH balance, pool owners can ensure a clean, healthy, and inviting swimming experience for years to come.

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


JimGalloway Author/Editor



KehlanPools-Why pH in Pools is Important



Are there specific skincare ingredients that affect pH?  Yes, certain ingredients commonly found in skincare products can affect pH. For example, acidic ingredients like alpha hydroxy acids (AHAs) and beta hydroxy acids (BHAs) can lower pH, while alkaline ingredients like some surfactants may raise pH.

Can I use skincare products with different pH levels together?  Yes, you can use skincare products with different pH levels together, but it’s essential to consider how they might interact with each other and with your skin. Layering products from lowest to highest pH is generally recommended to optimize absorption and minimize potential interactions.

How can I maintain the pH balance of my skin? To maintain the pH balance of your skin, use pH-balanced skincare products, avoid over-cleansing or over-exfoliating, and incorporate ingredients like niacinamide and ceramides that support the skin’s natural barrier function. Additionally, maintaining a healthy lifestyle, including staying hydrated and eating a balanced diet, can also contribute to skin health.

What is the ideal pH range for skincare products?  The ideal pH range for skincare products is typically around 4.5 to 5.5, which is similar to the skin’s natural pH. Products within this range are considered pH-balanced and are less likely to cause irritation or disrupt the skin’s protective barrier.

How can I tell if a skincare product has the right pH?  Some skincare products may indicate their pH on the packaging or in the product description. Alternatively, you can use pH testing strips or meters to measure the pH of a product at home.

What happens if skincare products have a high or low pH?  Skincare products with a high pH (above 7) can disrupt the skin’s natural pH balance, leading to dryness, irritation, and potential damage to the skin barrier. On the other hand, products with a low pH (below 4.5) may be too acidic and could also cause irritation or sensitivity for some individuals.



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