Simple Steps to Add Muriatic Acid In Pool Water: Safe and Easy

Do you know how to use muriatic acid in pool water? What are the different uses for it? Are there any side effects to using it? If you are wondering, then you are in the right place.

This article is perfect for anyone who wants to learn how to add muriatic acid in pool safely.

You’ll learn the overview of what muriatic acid is, why it is used, the precautions that should always be taken when dealing with this chemical, and finally, safe and easy steps to use it.

What is Muriatic Acid in Pool? 

Muriatic Acid is a strong acid that breaks down into water and chlorine gas. It is often referred to as hydrochloric acid by mistake and mixes well with water to help lower the pool’s pH.

Muriatic Acid is not a common household chemical but can be found in many home improvement or hardware stores in most places.

Muriatic Acid in Pool: Low pH value

As the name suggests, Muriatic Acid is a powerful acid (HCl). It has a pH of 0 which means it can react with things with a higher pH and lower their pH towards 0, which is acidic. Any pool or spa water that has a higher than 7.0 pH will undergo a rapid lowering of its PH when added to water due to the highly reactive nature of HCl.

This is great news for those who need to quickly lower their water’s PH for sanitation or disinfection purposes.

What Are the Benefits of Adding Muriatic Acid to Your Pool?

Adding muriatic acid to your pool helps control chemical levels in the pool. It’s easier to maintain an overall balanced pH level of your pool when you add muriatic acid. Many pool owners find that adding muriatic acid in pool water each week is a sure-fire way to maintain proper pH levels.

This chemical also helps disinfect pool water. Muriatic acid helps remove algae from your surface while lowering its PH level. This combination will impact the amount of algae in your pool and can help remove stubborn stains and spots that may be lingering.

Muriatic acid also helps dissolve some types of non-mineral deposits from your pool floor (not walls!). Dissolving this type of buildup will prevent it from causing damage to your equipment.

Muriatic Acid Precautions & Side Effects

Just like any strong chemical, you should take precautions when using it daily in your swimming pool or spa. Please check out the following warnings:

  • Unprotected skin should never be allowed to come into contact with the acid for long periods. Use rubber or latex gloves to minimize the exposure of your skin to this chemical. Improper use of gloves can result in severe burns that may require immediate medical treatment.
  • Always dilute a small amount of acid and test it on an inconspicuous area of your pool first before adding it to the entire area. This will help prevent any sudden changes from occurring in your pool’s chemistry if that’s not what you had intended when adding the acid.
  • Always remove all jewelry before adding acid. It’s highly recommended to have a chemical-resistant apron on during the entire process as well. After adding muriatic acid, the strong solution may cause abrasions to the skin and/or eyes if you go into your pool.
  • Don’t add any muriatic acid to a pool that has been recently refilled or has not yet started its filtering system. Instead, wait 24 hours before adding any acids so that all chlorine levels can dissipate from the water previously in the pool.
  • Consult a pool professional if you’re quite unsure of using muriatic acid. They can help you determine the proper amount of acid to be added, diluting it properly, and the health risks involved.

How to Safely Add Muriatic Acid In Pool Water

Understandably, adding muriatic acid in pool water might be intimidating. It’s a strong chemical with the ability to affect pH levels.

But don’t let this intimidate you and keep you from using it for its many benefits! Instead, follow these easy steps to help you add this chemical safely:

Step 1: Check Your Manual

Muriatic Acid in Pool: Manual

Check your owner’s manual for the recommended amount of muriatic acid your pool can handle.

Take note: If the instructions in a manual say to add muriatic acid but don’t give a specific amount, take this as a RED FLAG and find another pool manual to follow.

Step 2: Prepare All the Materials

Muriatic Acid in Pool: Preparing Materials

Make sure you have all the materials on hand that are needed to add the muriatic acid in pool water. This includes an empty bottle, eye protection (sunglasses are fine), rubber or latex gloves, and an accurate pH strip or test kit.

Step 3: Test Your Pool Water

Muriatic Acid in Pool: Test Pool Water

Test your pool for chlorine and pH levels before you add any acid. It’s important to know what you’re starting with so that you’ll be able to tell if your changes have been successful. 

Step 4: Dilute the Acid

The second and most essential step in properly adding muriatic acid in pool water is diluting the acid. When acid is added to pool water without first diluting it, the solution becomes considerably too concentrated. Diluting the acid enables the proper chemistry to be achieved before adding the acid to the pool water.

Before you dilute the acid, ensure not to add water to the acid. This will produce a violent reaction, resulting in the acid spraying out of the container and into you. Instead, to safely dilute the acid, start filling up a 4-5 gallon bucket with fresh water.

The amount of acid you add to the freshwater should be around 10% of the total volume of water. This translates to a 1/10 ratio of acid to water.

Step 5: Add the Acid to the Water

Muriatic Acid in Pool: Adding Muriatic to Pool

Finally, it’s time to add the acid to the water. Pour the solution around the pool, allowing it to disperse throughout the water.

When you’re adding acid, make sure you do it very slowly. Any splashes can burn your skin; that’s why extra precautions are necessary. Make sure no one can enter the pool for at least 30 minutes.

Step 6: Check the pH Level of Your Pool

Muriatic Acid in Pool: Testing Kit pH level

Now that the muriatic acid has been put in the pool, it’s time to check the pH levels once more. Bear in mind that this testing should take place just after a few hours.

If the readings remain excessively high, you can add very tiny volumes of muriatic acid to the pool water until the appropriate pH is reached. Then, retest the water every 3-4 hours until the pH readings reach the desired range of 7.2-7.8.

Muriatic Acid Vs. Hydrochloric Acid Vs. Sulfuric Acid

Muriatic Acid

Muriatic acid is a type of hydrochloric acid that can be diluted by adding water. When it comes to swimming pools, muriatic acid is safest to use, and it will not corrode the pool’s surfaces if appropriately used. However, when mixing it with other chemicals, such as pool plaster, muriatic acid can produce a whitening effect on the plaster because of the chlorine in the chemical.

It is important to know that no changes should be seen if you have a well-balanced pool (the pH levels are usually between 7.2-7.8). However, if the chemical is misused, you may see a whitening of the pool plaster.

Hydrochloric Acid

Hydrochloric acid is another type of strong acid that can be diluted by adding water. Along with muriatic acid, hydrochloric acid can damage the pool surface and cause corrosion if misused.

Hydrogen Sulphate solution is also included in swimming pool chemistry as a means of increasing pH levels. This chemical is used to treat and prevent scaling issues and can be found in different types of systems, such as a salt system or an algaecide system.

Sulfuric Acid

Sulfuric acid is a powerful chemical that can be diluted by adding water to it. When it comes to swimming pools, sulfuric acid is the most corrosive when not diluted properly.

If you use this chemical in your pool water incorrectly, it can cause severe damage to the pool surface and your health. Sulfuric acid is used for disinfection purposes in a pool or spa system.


Muriatic acid helps maintain the balance of your swimming pool’s water chemistry. And with everything in balance, you’ll spend less time scrubbing algae and more time enjoying your pool.

However, most importantly, use it with caution and adhere to all safety measures when using muriatic acid in pool water. If you have any queries or concerns, speak with a pool professional in your area.

View our collection of interesting pool articles. Here are some tips for cleaning and maintaining your pool. Enjoy a fun time in a clean, safe pool with your family!

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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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