Regarding pool care, alkalinity is one of the most important water quality factors to maintain. Alkalinity measures the water’s ability to neutralize acids and acts as a buffer to keep pH levels from fluctuating too much. It helps to prevent pH fluctuations, which can lead to eye and skin irritation. Additionally, high alkalinity levels can cause scale formation on pool surfaces and equipment.

It’s important to test the alkalinity levels regularly and adjust as needed. This guide will provide everything you need to know about lowering alkalinity in a pool. Let’s get started.

What Is Pool Water Alkalinity?

Pool water alkalinity measures the water’s ability to neutralize acids. The higher the alkalinity, the more resistant the water is to changes in pH.

Alkalinity is important because it helps to stabilize the pH of pool water. If the alkalinity is too low, the water will be more susceptible to changes in pH. This can cause swimmer comfort problems and lead to corrosion of pool surfaces and equipment.

What Does Low Alkalinity Do To A Pool?

Low alkalinity in a pool can cause the pH level to become unbalanced, leading to several problems. It can make the water more acidic, eroding pool surfaces and damaging pool equipment. It can also make it harder to maintain proper chlorine levels, leading to algae growth. Some associated issues include:

  • Corrosion: When the pH level is low, it can cause pool surfaces and equipment to corrode. This can lead to staining and etching of the pool surface and damage pool filters and pumps.
  • Algae Growth: Algae thrive in warm water with a low pH level. If the alkalinity in your pool is too low, it can make it harder to maintain proper chlorine levels, leading to algae growth.
  • Eye Irritation: Low alkalinity can also cause eye irritation for swimmers.

What Does High Alkalinity Do To A Pool?

High alkalinity levels can cause several problems in your pool, including:

  • High Calcium Levels: If your alkalinity is too high, it can lead to high calcium levels in your pool water. This can cause problems with your pool equipment and make it difficult to keep it clean.
  • pH Imbalance: High alkalinity levels can also cause a pH imbalance in your pool water. This can make it difficult to maintain proper pH levels and lead to problems with your pool equipment and swimmer comfort.
  • Cloudy Water: High alkalinity levels can also cause cloudy pool water. This is because the high alkalinity level causes the water to be more basic, which makes it harder for the chlorine to work effectively.
  • Uncomfortable Swimming: High levels can also make swimming uncomfortable. This is because the high it can irritate your skin and eyes.

What Causes High Pool Alkalinity?

A few factors can cause high alkalinity in your pool, and it’s important to be aware of them so you can take steps to correct the issue.

1. Use Of Hypochlorite Chlorine

One common cause of high alkalinity is using the wrong type of chlorine. Some types of chlorine, such as calcium hypochlorite, can raise the alkalinity levels in your pool. If you suspect that your pool’s alkalinity is too high, check the labels on your chlorine products to see if they contain calcium hypochlorite. Also, be sure to test the alkalinity levels regularly so you can catch any issues early.

2. Use Of Borax To Raise The PH

Borax is another common cause of high alkalinity. This is because borax raises your pool’s pH; as the pH rises, so does the alkalinity. If you’re using borax to raise your pool’s pH, test the alkalinity levels regularly so you can adjust as needed.

3. Evaporation

Evaporation can also cause high alkalinity levels in your pool. As water evaporates, it leaves behind minerals, including calcium carbonate. This can raise the alkalinity levels in your pool over time. To combat this, regularly add fresh water to your pool to keep the levels balanced.

4. High Total Dissolved Solids Levels

High levels of total dissolved solids (TDS) in your pool measure all the dissolved materials in your pool water, including minerals, salts, and metals. If your TDS levels are too high, it can cause an increase in alkalinity. You can use reverse osmosis or deionization filter to lower your TDS levels.

5. Curing Of Pool Plaster

With newly plastered pools, the curing process can also cause high alkalinity levels. This is because the plaster contains calcium carbonate, which will dissolve into the water and raise the alkalinity. To prevent this, be sure to have your pool tested before adding any new plaster.

6. High pH Water

With high pH water, the alkalinity levels will also be high. This is because the two are directly related. As the pH rises, so does the alkalinity. If your pool’s pH is too high, you can use a pH reducer to lower it.

If you suspect your pool’s alkalinity levels are too high, it’s important to correct the issue. Test the alkalinity regularly and add fresh water to your pool as needed. You may also need to adjust your pool’s pH or use a different type of chlorine.

How to Test Total Alkalinity in a Pool?

To test the TA level in your pool, you will need to purchase a test kit that measures alkalinity. Test kits are inexpensive and can be found at most pool supply stores. Once you have your test kit, follow the instructions that come with it to test the TA level in your pool water properly.

Mainly, you need to submerge the test strip in the water for a few seconds, then compare the strip’s color to the TA chart that came with the kit.

How to Lower Alkalinity in a Pool?

Lowering alkalinity can be important for several reasons. It can prevent staining and scale build-up on pool surfaces and make the water more comfortable for swimmers by reducing eye irritation. There are a few different chemicals that can be used to lower high levels, including:

1. Muriatic Acid  

Muriatic acid, similar to hydrochloric acid, is a great way to lower the alkalinity in your swimming pool. All you need to do is add the acid to your pool water and let it circulate for a few hours. Be sure to test the pH levels regularly and add more acid if necessary.

Also, the amount of muriatic acid you’ll need to add will depend on the size of your pool and the current alkalinity levels. You can also dilute it as per manufacturer instructions. Remember not to add too much, as it can lower the pH levels of your pool water and make it more acidic.

2. Sodium Bisulfate

Sodium bisulfate is another popular choice for lowering alkalinity in pools. It’s a granular powder that you can add directly to your pool water. You’ll need to start with a lower dosage and gradually increase it until you reach the desired alkalinity level.

Also, make sure you test the pH levels regularly and adjust accordingly. Too much sodium bisulfate can make your pool water more acidic, so be careful not to overdo it.

You can use a few other chemicals to lower alkalinity in your pool, but these are two of the most popular and effective options. 

You can also use a product that will bind with alkaline molecules, such as sodium thiosulfate. This chemical can be especially helpful if you have high calcium levels in your pool water, as it will also help lower the calcium hardness. Also, sodium bicarbonate and sodium carbonate are good options to consider.

Be sure to follow the manufacturer’s instructions and safety precautions when using any chemicals in your pool. 

How To Lower Alkalinity Without Lowering pH?

To ensure that water levels are correctly balanced, pool owners should test for both alkalinity and pH. Alkalinity measures the water’s ability to neutralize acids, while pH measures the actual acidity or basicity of the water. While lowering alkalinity will lower pH, remember to maintain pH levels within the recommended range of 7.2 to 7.6. Otherwise, swimmer safety could be at risk.

If you need to make a large adjustment to the alkalinity levels in your pool, it’s best to do it gradually. This will allow your pool time to adjust and minimize potential problems. Test the alkalinity levels frequently and add chemicals until the desired level is reached.

With proper care and attention, you can keep your pool’s alkalinity levels balanced and ensure that everyone who uses it enjoys a safe and enjoyable experience.

FAQs

Does Chlorine Increase Alkalinity?

Yes, chlorine does increase alkalinity. Chlorine is a chemical used to disinfect pool water and keep it clean. When added to water, chlorine raises the pH level and makes the water more alkaline.

Does Pool Shock Lower Alkalinity?

Yes, pool shock can lower alkalinity. Pool shock is a powerful oxidizer that can break down organic matter and lower the pH of pool water. When used in large doses, pool shock can lower alkalinity levels too much, so it’s important to use it sparingly and only as needed.

What is the Best Way to Lower Alkalinity in a Pool?

The best way to lower alkalinity in a pool is to use a product specifically designed for that purpose. Many different products on the market can lower alkalinity, but not all of them are created equal. Be sure to read the label carefully and follow the directions to avoid damaging your pool or making it unsafe for swimming.

How Often Should I Test My Pool’s Alkalinity Levels?

You should test your pool’s alkalinity levels at least once a week. Test more frequently if you have reason to believe that the levels are changing rapidly. Remember, it is important to maintain proper alkalinity levels in your pool to keep it safe for swimming and prevent long-term damage to its surfaces and equipment.

What Happens If My Pool’s Alkalinity Levels Are Too High?

If your pool’s alkalinity levels are too high, it can cause calcium deposits to form on surfaces, cloudiness in the water, and problems with pH balance. In extreme cases, high alkalinity can even cause the etching of pool surfaces.

What Should Be Adjusted First Alkalinity Or pH?

It is recommended that you adjust alkalinity first and then pH. This is because pH can be affected by changes in alkalinity. Adjusting alkalinity first can help prevent drastic swings in pH levels that can damage your pool.

Does Rain Increase Alkalinity In Pool?

Yes, rain can increase alkalinity levels in a pool. When rainwater falls into a pool, it can dissolve minerals from the surrounding environment and raise the water’s alkalinity level. Be sure to test your pool’s alkalinity levels after a heavy rainstorm and adjust as needed.

Conclusion

With all of the information above, it is clear that there are a few different ways that you can go about lowering the alkalinity in your pool. You will want to make sure that you test your water frequently so that you can catch any issues early on and prevent them from becoming bigger problems.

We hope that this guide has been helpful and that you feel more confident about lowering the alkalinity in your pool.

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Last Updated: November 20, 2022 / Categories: Outdoor & Garden, Pool & Spa / 9.4 min read / Tags: , , /

About the Author: Brian Stilts

Brian Stilts

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