Is It Safe to Swim in a Pool with High Alkalinity?

Swimming pools provide a refreshing escape, especially during hot summer days. While you may be tempted to dive in without a second thought, first consider the quality and safety of the water you’re swimming in.

Among the factors that may impact the pool experience is alkalinity, which refers to the ability of the water to neutralize acids. Understanding and maintaining the right alkalinity levels in your swimming pool is crucial for both the health of the swimmers and the pool itself. So, is it safe to swim in a pool with high alkalinity?

can you swim with high alkalinity

No, it is not safe to swim in a pool with high alkalinity. Doing so can cause irritation of your skin and eyes. Moreover, high alkalinity can result in cloudy water, clogged filters, and an increased buildup of dirt. Aim to keep the alkalinity within the recommended range of 80 to 120 parts per million (ppm) to avoid these problems.

Keep reading to better understand what exactly alkalinity does to your pool both good and bad, what it can do to swimmers, and how to keep it balanced.

Understanding pH and Alkalinity in Pools

To maintain a healthy swimming environment, it’s crucial to understand and manage the pH and alkalinity levels in your pool.

The pH level measures how acidic or basic the water is, with values below 7 being acidic and values above 7 being alkaline or basic. The ideal pH range for swimming pools is between 7.4 and 7.6, although a range of 7.2 to 7.8 is generally considered acceptable. This range helps keep swimmers’ skin and eyes comfortable, as well as protect pool surfaces from corrosive damage, stains, and scale buildup.

Alkalinity, on the other hand, refers to the pool’s ability to resist changes in pH levels. Compounds like carbonate, bicarbonate, and hydroxides are all alkaline and help neutralize acids. High alkalinity keeps the pH level stable, while low alkalinity can cause wild fluctuations in pH. Ideally, you should maintain total alkalinity levels between 80 and 120 parts per million (ppm) to ensure steady pH levels.

Balancing pH and alkalinity is an essential part of pool maintenance, as imbalances can lead to uncomfortable conditions for swimmers and potential damage to your pool. For instance, when you experience pH fluctuations, you might need to use chemicals like sodium bicarbonate (baking soda) or soda ash to adjust the pH. Similarly, to raise the alkalinity, you can use an alkalinity increaser, typically made from specific chemicals like bicarbonate salts.

High alkalinity in pools is when the concentration of alkaline compounds exceeds the recommended levels, which can cause the water to become cloudy and lead to scaling and reduced effectiveness of pool chemicals. While the water may not be unsafe for swimming at slightly elevated alkalinity, it can cause discomfort and irritation to swimmers’ eyes, as the ideal pH range for eye comfort is between 7.2 and 7.8.

Effects of High Alkalinity on Swimmers

Swimming in a pool with high alkalinity levels may not necessarily be unsafe, especially if the water contains adequate chlorine and has a balanced pH level. While high alkalinity may not directly harm you,, it’s important to understand the potential effects on swimmers to ensure a comfortable and enjoyable experience.

High alkalinity can lead to skin irritation and burning eyes for swimmers. When your pool water has high alkalinity, it can cause the pH to rise and become unbalanced. This can result in cloudy water, scaling, weak sanitizer, and discomfort for your eyes and skin. You should check and correct both alkalinity and pH levels often to prevent these issues.

Another potential effect of high alkalinity is the reduced effectiveness of the pool’s disinfecting agents, such as chlorine. As you know, chlorine is the primary disinfecting agent used for sanitizing the pool water, and anything that reduces its effectiveness makes the pool environment less safe for swimmers.

Impact on Pool Equipment

When there’s high alkalinity in your pool, it can affect various pool equipment and structures, such as filters, pumps, ladders, and pool surfaces.

First off, high alkalinity can lead to scaling and calcium deposits. Scaling refers to the buildup of calcium and other minerals on pool surfaces and equipment. This scaling can become a problem on your pool’s plaster, metal, and other surfaces.

It can also cause calcium deposits to form on essential pool equipment like pumps, filters, ladders, and returns. If these deposits accumulate excessively, it can lead to damage, reduced efficiency, and higher maintenance costs for your pool equipment.

Adjusting Pool Water Chemistry

Increasing Pool Alkalinity When It’s Too Low

Materials Needed: Baking soda (sodium bicarbonate) or a pool-specific alkalinity increaser product.

  1. Test Your Water: Begin by using a reliable pool test kit or test strips to determine the total alkalinity level. The ideal range is typically between 80-120 ppm.
  2. Calculate the Required Amount: Based on your test results, determine the amount of baking soda or alkalinity increaser you need. Follow the manufacturer’s instructions or use online pool calculators.
  3. Turn Off the Pool Pump: Before adding chemicals, ensure the pool pump is turned off.
  4. Add Baking Soda or Alkalinity Increaser: Slowly add the determined amount of baking soda or alkalinity increaser to the pool. Distribute it evenly across the pool’s surface.
  5. Turn On the Pool Pump: After adding the baking soda or increaser, turn on the pool pump. This will help circulate the chemicals and ensure even distribution.
  6. Wait and Re-test: Wait for at least 4 hours, then re-test your pool’s total alkalinity. If it’s still too low, repeat the process.

Decreasing Pool Alkalinity When It’s Too High

Materials Needed: Muriatic acid or sodium bisulfate (often labeled as dry acid or pH decreaser).

  1. Test Your Water: Start by using a reliable pool test kit or test strips to determine the total alkalinity level.
  2. (Situational) Aerate the Pool. If your pool alkalinity is too high while the pH is too low, then aerate your pool first. By increasing the water’s oxygen content through aeration, you can help raise the pH levels without increasing the alkalinity further. Aeration can be done by using water features like fountains or waterfalls or by aiming the return jets towards the surface of the pool.
  3. Calculate the Required Amount: Depending on how high the alkalinity level is, calculate the amount of muriatic acid or sodium bisulfate needed. Note that muriatic acid will decrease both alkalinity and pH. If you’ve aerated the pool, then the increased pH will act as a buffer so that it won’t drop too low while decreasing the alkalinity. Always follow the manufacturer’s instructions or consult an online pool calculator for accurate dosage.
  4. Safety First: When handling chemicals, especially muriatic acid, wear safety goggles and gloves. Ensure the area is well-ventilated.
  5. Turn Off the Pool Pump: Before adding chemicals, ensure the pool pump is turned off.
  6. Add Muriatic Acid or Sodium Bisulfate: If using muriatic acid, always add acid to water, never the reverse. Slowly pour the acid along the deep end of the pool, keeping it away from the pool’s sides. If using sodium bisulfate, distribute it evenly across the pool’s surface.
  7. Turn On the Pool Pump: After adding the chemicals, turn on the pool pump to circulate and evenly distribute the acid or bisulfate.
  8. Wait and Re-test: Wait for at least 4 hours, then re-test your pool’s total alkalinity. If it’s still too high, you may need to repeat the process.

Frequently Asked Questions

What are the effects of swimming in a pool with high alkalinity?

Swimming in a pool with high alkalinity can cause water imbalances, leading to cloudy water, skin and eye irritation, and an unchecked rise in pH levels. Pools with high alkalinity might also have issues with pool equipment, such as clogging or scaling of filters. However, it is not considered dangerous to swim in a pool with high alkalinity, but it may cause discomfort to those with sensitive skin or eyes.

How can I reduce alkalinity in my pool without impacting pH?

Reducing alkalinity in your pool without impacting pH can be tricky, as both parameters are intertwined. However, one method is to use a product specifically designed to lower alkalinity without affecting pH, such as sodium bisulfate or certain acids. For best results, follow the manufacturer’s instructions and test your pool water regularly to ensure proper balance is maintained.

What are common causes of increased alkalinity in pools?

Common causes of increased alkalinity in pools include overuse of alkaline substances, such as certain pool chemicals or even household cleaning products. Additionally, heavy rain or top-off water can also cause alkalinity to rise if the source water has high alkalinity levels. It’s important to monitor and adjust your pool’s alkalinity regularly to maintain a healthy swimming environment.

Should I avoid swimming in a pool if the alkalinity is over 180?

While it’s not necessarily dangerous to swim in a pool with alkalinity over 180, it may cause discomfort for swimmers with sensitive skin or eyes. It’s best to lower the alkalinity to a proper range (80-120 ppm) and balance other water chemistry parameters to provide a comfortable and safe swimming environment.

How quickly can I lower the alkalinity in my pool?

Lowering the alkalinity in your pool can be done relatively quickly. After adding chemicals like muriatic acid or sodium bisulfate in the deepest area of your pool, you may see a reduction in alkalinity levels within a few hours. It’s important to keep circulating the water and retesting the levels to ensure proper balance is reached.

Is it unsafe to ingest pool water with high alkalinity?

While it’s not ideal to ingest pool water with high alkalinity, small accidental amounts shouldn’t pose a significant health risk. However, large quantities of pool water ingestion can lead to potential health issues or discomfort, regardless of the alkalinity level. It’s important to not drink pool water and to keep an eye on children to ensure they avoid ingesting it as well.