Best Way to Lower Pool’s pH Levels: Sodium Bisulfate and Muriatic Acid

The best way to lower pool’s pH levels is to use sodium bisulfate and muriatic acid. These chemicals are the most effective for adjusting pool pH, but you need to know how to use them safely. Here are some tips!

Whether you’re a pool owner or a swimmer, you need to make sure that the pH level in your pool is at around 7.2-7.5 for it to be safe. But how do you even lower pool’s pH levels?

Testing Kit pH level

The key is adding muriatic acid, which will rapidly bring the pH levels down by releasing CO2 gas into the water and effectively lowering the pH level of your swimming pool.

While this requires some additional pool chemicals and effort, it’s important to keep swimming pools within safe limits so people can enjoy them without worrying about their health or safety. If done correctly, it will ensure that your pool stays well balanced and healthy, doing no harm to your pool.

If you don’t add the right amounts of pool chemicals, or if you don’t take the proper safety precautions during the process, there is a huge chance these acids can damage your pool. Fortunately, there are ways you can do to make the process a lot easier, and in this guide, we’ll go over everything there is to know how to lower pool’s pH levels. 

What Are the Effects of High pH Levels in Swimming Pools?

The pH of pools can be acidic, basic, or neutral. The pH level also directly affects the water’s disinfectant strength and effectiveness. Pools with a high pH make the water corrosive because of the high chlorine presence and other substances.

Here are some problems of high pH levels in pools that you might have to deal with:

  • You’ll see swimmers complain about stinging eyes, dry and a sticky feeling in their skin.
  • Your pool turn hazy or cloudy, which is very unpleasant for swimmers.
  • Chlorine loses its effectiveness at pools with high pH levels. For pool owners, adding chlorine due to high pH levels accumulates over time, so it can be expensive than pH testing kits. 
  • High pH levels add more alkalinity to the water and cause calcium buildups. This clogs your filters and pipes, and eventually strain pool equipment and cause various pool problems (leaks, motor failure, etc.)

Why Is Your Pool’s pH Balance High?

High pH level

pH levels in pools can be acidic, basic, or neutral. Several factors could result in a pool’s high pH level. Some of which are:

  • Tarnish (rust) on the pool wall can lead to increased levels of metal ions in the water.
  • Increasing chlorine levels over time may cause an increase in combined chlorine, which can also lead to pH increasing due to high concentration of chloramines (banned for public pools).
  • Various minerals in the water are dissolved by the water reaction to the pool wall.
  • Lack of pool maintenance and chemical imbalance. Frequent use of pool chemicals also causes an increase in pH levels. 
  • Swimming pool owners who drain out their swimming pools and add fresh water will directly cause the pH levels to change as well. The process of adding new water can raise pH levels because minerals present in the tap water can dissolve into the swimming pool.

How to Lower Pool’s pH Levels?

Sodium bisulfate and muriatic acid are the two primary pool chemicals often used to decrease the pH levels in swimming pools.

It’s important to note that both chemicals damage the pool surface and the skin, so try and use it with high precautions. Best to wear clothing that fully covers your body, as well as gloves and goggles for safety. 

Sodium Bisulfate

Sodium Bisulfate

Sodium Bisulfate is a chemical that will help reduce the pH levels in swimming pools. This happens because sodium bisulfate reacts with water to produce sulfuric acid, further reducing the pH levels. 

Sodium Bisulfate is marketed as a safe alternative for swimming pool owners because it doesn’t contain any chlorine. Still, if not used correctly, it can be dangerous and harmful to humans and animals in contact with it.

Muriatic Acid

Adding Muriatic to Pool

Muriatic acid is a chemical commonly used by pool owners and professionals to lower the pH levels in swimming pools. Muriatic acid is a strong acid with the chemical formula HOCl. It’s also one of the most commonly used pool chemicals for pool owners to control algae blooms and bacterial growth in pools.

Though muriatic acid can be transferred into humans via inhalation or skin contact, it’s very safe when used correctly at the proper concentrations.

How to Lower Pool’s pH Levels Using Sodium Bisulfate?

If you decide to use a sodium bisulfate product to reduce your pH or alkalinity levels, ensure to follow the instructions carefully. One more thing is to avoid the process during windy days because the wind may blow back the powder/liquid and burn your skin and eyes.  

Sodium Bisulfate

Here are some steps you can follow:

Step 1: Know the pH and Alkalinity Levels

The pH level should be somewhere 7.2 and 7.6, and the alkalinity level should be around 80 and 120 parts per million (ppm). After determining that the levels are excessive or too low, it’s time to work on them.

Step 2: Measure the Pool Chemicals

Read the manufacturer’s instructions to learn how much product to add based on the levels you need to increase or decrease. 

Step 3: Pour the Chemicals Straight Into the Return Jet’s Sites

Pour the powder form directly into your return jet sites. These are the spots where water enters the pool. Avoid adding it to the skimmer at all costs.

Above-ground pools will almost certainly require you to circulate the water yourself and spread the chemical evenly around the pool with your own hands.

Step 4: Wait Patiently for the Pool Chemicals to Dissolve

Let the filtration system do its job and distribute the chemical. If your filtration system is functioning properly, then the chemical should dissolve completely at approximately 15 minutes.

Step 5: Retest the Levels and Repeat the Process as Necessary

We advise not to test the levels immediately or wait 24 hours to let the chemicals do their work. 

If your pH and alkalinity readings come back in the normal range, then your work is done.  However, if they are still too high, repeat the process. But make sure this time, you increase the amount by approximately 3/4 of what the instructions demand.

How to Decrease the Pool’s PH Level Using Muriatic Acid?

Muriatic Acid

Step 1. Know the PH and Alkalinity Levels

The pH level should be somewhere 7.2 and 7.6, and the alkalinity level should be around 80 and 120 parts per million (ppm).

If you’ve already tested and the levels are too high, muriatic acid will help you lower them.

Step 2. Measure the Pool’s Chemicals

Read and follow the manufacturer’s instructions thoroughly to know how much you’ll need to add based on how much you need to raise the levels. 

Step 3. Add the Muriatic Acid

There are two ways on how you can add muriatic acid to your pool. 

One method is to switch off the pump and pour the liquid into the pool in a tiny, steady stream at the pool’s shallow end. This allows the acid to sink to the pool rather than merely float on top. After that, you may re-start the pump and allow it to circulate the water.

Step 4. Wait Patiently for the Chemicals to Dissolve

Keep the filtering system running for about 2-6 hours to widely distribute the chemical to your pool.

Step 5. Retest the Levels and Repeat the Process as Necessary

Retest your pH and total alkalinity levels. If your pH and alkalinity readings come back within the normal range, then your pool is good to go. 

However, if they are still too high, repeat the process, increasing the amount by approximately 3/4 of what the instructions demand.

Tips for Keeping PH Levels in the Pool Balanced

  • Test your pool chemistry at least twice a week. If you’ve been having problems with pH balance, check it every day until you have it under control. This might appears as a major pain in the you-know-what. However, it only takes a few minutes of your time versus the hours you could be spending trying to fix the situation.
  • Regularly clean your pool. Items such as filthy leaves and small debris can impact the pH balance of your pool. It’s best to use a pool skimmer to remove the debris from the pool every day. It’s a good way to make kiddos earn their money.
  • Regularly inspect your filtration system. If your pool filter is doing a fine job, it will take a lot less work to keep the water balance, clean, and healthy. 
  • Regularly shock your pool. Most pool experts recommend shocking your pool at least once a month, but you should do it more frequently during high usage or the weather’s changing. Shocking the pool can help restore all the chemical levels back to normal levels.

A Brief Overview of Pool Maintenance Essentials

1. Pool Chemicals: Why Tablets?

Chlorine and bromine are available in various forms, but tablets stand out for convenience. Remember, bromine tablets dissolve slower than chlorine, impacting pool water balancing.

2. Cloudy Water & Cyanuric Acid

Cloudy water in outdoor pools often links to low cyanuric acid levels, which also causes faster chlorine depletion. Regularly check and adjust stabilizer levels to avoid this issue.

3. Sunlight & Chlorine Efficiency

Sunlight rapidly breaks down pool chlorine. However, Pool Chlorine Tablets can combat issues like algae growth, ensuring a clean pool. A balanced pH enhances chlorine’s effectiveness.

4. Combatting Algae Growth

Without proper chemicals, algae growth becomes a threat. Using algae preventers inhibits this problem.

5. Stabilizers: Cyanuric Acid’s Role

Cyanuric acid or CYA, also termed as a stabilizer, is vital for pool health. To boost CYA levels, add stabilized chlorine or a dedicated pool stabilizer.

6. Diverse Water Chemistry Aspects

Beyond pH, consider total alkalinity, calcium hardness, and CYA. Commercial pool operators routinely monitor these elements.

7. Regulating pH with Soda

pH is influenced by various factors, including Calcium Hardness. To adjust pH, Soda Ash or even baking soda can be effective.

In essence, smart pool maintenance involves understanding tablets’ role, monitoring cyanuric acid for clear water, combating algae, and managing pH using common substances like soda.

Frequently Asked Questions (FAQs)

Can I lower pH levels by adding more chlorine?

Chlorine can lower pH levels to some extent, but it’s not the most effective method and can affect other water parameters.

How long does it take for pH levels to adjust after adding chemicals?

pH adjustments can take a few hours to a day to stabilize. Retest and make further adjustments if needed.

What is the risk of having pH levels too low (acidic) in a pool?

Extremely low pH levels can corrode pool equipment and irritate swimmers’ eyes and skin.

How do I prevent pH levels from constantly rising in my pool?

Properly manage the use of pool chemicals, ensure good circulation, and monitor water balance to prevent pH fluctuations.

What are the consequences of not maintaining the right pH level in a pool?

Imbalanced pH levels can lead to ineffective chlorine, scaling, cloudy water, and discomfort for swimmers.


After you’ve stabilized the pH level in your pool, or if you’re having a lot of difficulties doing so, go ahead and test the entire pool chemistry to determine whether you need to add chlorine or make any other adjustments.

Maintaining your pool’s cleanliness and overall condition can help to ensure that fewer problems develop in the long run. But if they do, come back here because we have got answers to your questions! View our collection of interesting pool articles. Here are some tips for cleaning and maintaining your pool.

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About the author

Brian Anderson

The rather dry pool world out there is in need of some passion to make it shine. With the help of my son Ruben and his wife Maria our mission is to help you create the favorite spot of your house - your pool.

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