Sodium bisulfate, also known as dry acid, is a popular choice for lowering pH and alkalinity in swimming pools. It’s easy to use and relatively inexpensive, making it a go-to option for many pool owners.

But with so many products on the market, it can be tricky to know which sodium bisulfate is best for your pool. In this guide, we’ll break down everything you need to know about sodium bisulfate and help you choose the right product for your needs. Let’s get started.

What Is Sodium Bisulfate?

Sodium bisulfite is a chemical compound with the formula NaHSO4. It is a white solid that is highly soluble in water.

It is commonly used as a pH adjuster in pools or hot tubs. When used in pools, it lowers the pH of the water, making it more acidic. This can be beneficial as it helps to prevent the growth of algae and bacteria. In hot tubs, sodium bisulfate can lower the water’s pH, making it more comfortable for people to soak in.

What is Sodium Bisulfate Used For?

Sodium bisulfate is used for various purposes, most commonly as a pH adjuster or acidifier. It can be found in many different products, including pool chemicals, cleaning products, and food additives.

When used in pools, sodium bisulfate lowers the pH level of the water, making it more acidic. This can be beneficial as it makes it harder for algae to grow and helps to keep the water clean. It can also help to prevent calcium buildup on pool surfaces.

Best Sodium Bisulfate for Pools

To keep your pool clean and sparkling, you must regularly add chemicals. One of the most important chemicals is sodium bisulfate, also known as pH down. There are many brands of sodium bisulfate on the market, so how do you know which one to choose? We’ve rounded up the best options below, which are highly effective at keeping pools clean and balanced.

1. EcoClean Solutions pH Down

No products found.

If your pool’s pH levels get too high, it could put swimmers at risk of getting sick or skin irritation. The water can also become dull and cloudy and damage pool equipment and surfaces. Fortunately, lowering the pH level is a simple process that can be done quickly with a pH reducer. This pH reducer is made from granular sodium bisulfate, a safer and less corrosive alternative to muriatic acid. It re-establishes an ideal pH level to prevent skin irritation and damage to pool equipment.

EcoClean Solutions pH Down is a concentrated granular sodium bisulfate that is biodegradable and non-toxic. It is safer than muriatic acid, and 10 lbs. of granular pH reducer equals 1 gallon of muriatic acid. It is also easy to store and use less of, making it more economical. The initial dosage for pools is 15-30 oz per 10,000 gallons.


  • Lower the pH levels in your pool.
  • 100% sodium bisulfate is a natural and effective way to lower pH levels.
  • Easy to use, add it to your pool water, and it will start working immediately.
  • Affordable, making it a great option for those on a budget.


  • Difficult to dissolve in-pool water.

2. Leisure Pool 25 lb. pH Decreaser

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Leisure Pool, 25 lb. pH Decreaser, is the perfect product to keep your pool’s pH levels in check. Made with sodium bisulfate, this pH decreaser is specially formulated to lower the pH of your pool water quickly and effectively. With its easy-to-use design, simply sprinkle the desired amount into your pool and watch as the pH levels drop.

This product keeps your pool’s pH levels at their optimal level. This dry powder is perfect for lowering pH levels in commercial and residential swimming pools and spas. For dosage calculations, 10 lb. of our product will lower the pH level by 0.2 per 120,000 gallons of water. Simply add it to your pool water as needed and enjoy crystal clear, great-tasting water all season long. Order your product today and enjoy worry-free swimming all season long.


  • Quickly and effectively lowers pH levels
  • Easy to use
  • Keeps pH levels at their optimal level


  • The product doesn’t seem to work as well as other brands.

Best Sodium Bisulfate for Pools

ImageBest Sodium Bisulfate for PoolsAverage Customer Review Link
EcoClean Solutions pH Down4.6/5Amazon
Leisure Pool 25 lb. pH Decreaser4.5/5Amazon

Sodium Bisulfate Vs. Muriatic Acid

You should be aware of a few key differences between sodium bisulfate and muriatic acid before using either one to clean your pool.

  • Sodium bisulfate is a dry, granular chemical that is added to water to lower the pH levels. It is often used in swimming pools that have high alkalinity levels.
  • On the other hand, Muriatic acid (Hydrochloric Acid) is a liquid chemical used to lower the pH and total alkalinity levels in swimming pools. It is also used to remove calcium deposits from pool surfaces.

So, which one should you use to clean your pool?

If you have a high alkalinity level in your pool, sodium bisulfate is the better choice. It will lower the pH levels without affecting the chlorine levels. Muriatic acid is better if you need to remove calcium deposits from your pool surfaces. It will also lower the pH and total alkalinity levels in your pool.

As always, follow the manufacturer’s instructions carefully when using either one of these chemicals. And, if you have any questions, ask a professional before using either chemical in your pool.

How to Lower pH With Sodium Bisulfate?

To lower the pH of your pool with sodium bisulfate, also called dry acid, you’ll need to follow these steps:

1. Test Your Pool pH Levels

First, you need to test your pool water to see the current pH levels. You can purchase a swimming pool test kit from your local hardware store or online.

2. Add the Sodium Bisulfate

Once you know how much sodium bisulfate is needed to lower your pool’s pH, you can add it directly to the water. Be sure to do this when nobody is swimming in the pool and follow the manufacturer’s directions.

3. Let The Product Work

After adding the sodium bisulfate, you’ll need to wait for it to work. The pH levels of your pool should start to lower within a few hours.

3. Test the Pool Water Again

After you’ve added the sodium bisulfate, it’s important to test the water again to ensure that the pH levels have been lowered to where you want them. If not, you can add more sodium bisulfate until you reach the desired pH level.

Sodium bisulfate is a popular choice for lowering pH levels in pools because it’s effective and easy to use. Follow the steps above carefully to ensure that your pool water is at the perfect pH level for swimming.

How to Lower Alkalinity with Sodium Bisulfate?

Many people ask how to lower alkalinity in their pool with sodium bisulfate. While it is true that this chemical can be used to lower the pH levels of your pool, it is important to understand how to use it first properly. Here is a step-by-step guide on effectively lowering the alkalinity in your pool & pH using sodium bisulfate.

1. Test The pH

The first thing that you need to do is to test the alkalinity level of your pool water. You can use a pH testing kit or a digital pH meter. It is important to know the current pH level of your pool water to determine how much sodium bisulfate is needed to lower it.

2. Calculate The Amount Of Sodium Bisulfate

Once you know the current pH level of your pool, you can now calculate the amount of sodium bisulfate needed to lower it. To do this, you will need to use a calculator or an online alkalinity calculator.

3. Add The Sodium Bisulfate

After calculating the amount of sodium bisulfate needed, you can now add it to your pool water. It is important to note that you should never add more than the recommended amount as this can damage your pool and make it unsafe for swimming.

Be sure to dilute the sodium bisulfate in a bucket of water before adding it to your pool. Also, let it rest for 6 hours after addition.

4. Test The pH Again

After adding the sodium bisulfate, it is important to test the pH level of your pool water again. This will help you determine if you have added the right amount or if you need to add more.

5. Adjust The Amount Of Sodium Bisulfate

If the pH level of your pool is still not at the desired level, you can adjust the amount of sodium bisulfate accordingly. Just be sure not to add too much, as this can damage your pool.

This is a quick and easy guide on how to lower alkalinity in your pool with sodium bisulfate. Just be sure to follow the instructions carefully and test the pH levels regularly to ensure that your pool is safe for swimming.

Also Read: Flocculant For Pool


Is Sodium Bisulfate Unhealthy?

Sodium bisulfate is not considered to be unhealthy when used in small doses. In fact, it is commonly used as a food additive and preservative. However, sodium bisulfate can be dangerous if inhaled or ingested in large amounts. Symptoms of sodium bisulfate poisoning include coughing, wheezing, and difficulty breathing. If you experience any of these symptoms after using sodium bisulfate, seek medical attention immediately.

What Can I Use Instead Of Sodium Bisulfate?

There are a few different chemicals that can be used in place of sodium bisulfate. These include potassium bisulfite, sodium chloride, sulfuric acid, calcium chloride, and magnesium sulfate. Each of these chemicals has different properties and applications, so be sure to choose the one best suited for your needs.

Is Sodium Bisulfate The Same As Soda Ash?

No, sodium bisulfate is not the same as soda ash. Soda ash is a much weaker acid salt and is not as effective at lowering pH levels in swimming pools.

How Do I Use Sodium Bisulfate?

Sodium bisulfate can be added to swimming pools to lower the pH level. It is important to follow the manufacturer’s instructions when using this chemical. Too much sodium bisulfate can make the pool water too acidic, harming swimmers.

How Often Should I Add Sodium Bisulfate To My Pool?

The frequency with which you add sodium bisulfate to your pool will depend on the pH level of the water. You should test the pH levels regularly and add sodium bisulfate as needed to keep the pH levels within the recommended range.

Also Read: Best Algaecide For Pools


When it comes to keeping your pool clean and free of algae, sodium bisulfate is one of the best options on the market. Not only is it effective at preventing and eliminating algae growth, but it is also relatively affordable and easy to find. In addition, sodium bisulfate is safe for humans and animals, making it a great choice for those concerned about the environment.

We hope our guide has helped you understand more about sodium bisulfate and how it can benefit your pool. If you have any further questions, please contact us and we will be happy to assist you.

Last Updated: November 20, 2022 / Categories: Outdoor & Garden, Pool & Spa / 9.2 min read / Tags: , , , , , , /

About the Author: Brian Stilts

Brian Stilts

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