Sodium Bisulfate in Your Pool – The Easy Guide

Michael Keenan


Pool Water Chemistry

If you own a swimming pool or spa, you should already know what sodium bisulfate is. Sodium bisulfate is a chemical used to lower the pH level in chlorinated water, as well as the alkalinity level when it also gets too high.

Sodium bisulfate is one of the most popular products used to maintain these levels because it is water-soluble, eco-friendly, biodegradable, and inexpensive.

This article will cover everything from how often you need to check the levels and what numbers they should be between, as well as tips on diluting sodium bisulfate correctly before adding it to your pool. With this information in hand, you can easily keep your swimming pool at its optimum level of safety!

Also known as sodium hydrogen sulfate, sodium bisulfate is a dry acid that is sort of grainy, and you can store it in a container and use it as needed. In addition to swimming pools and hot tubs, it is also used as a food additive and even a cleaning agent. Who knew?

sodium bisulfate in pools

Quick Answer:

Sodium bisulfate is an inexpensive, eco-friendly chemical used to lower the pH and alkalinity levels in swimming pools and hot tubs. It’s important to keep these levels within a certain range (7.2-7.8 for pH; 80-120 ppm for alkalinity) for safe swimming conditions and to prevent corrosion, cloudiness, and bacteria growth.

It’s easy to use by following manufacturer instructions and waiting 6 hours before getting back into the water after adding it. Keep on reading for the full guide!

The Optimum pH Level

For you and your family to swim safely in your pool, the pH level has to be a certain number, with most experts recommending that it remain between 7.2 and 7.8 at all times. If it gets too high or too low, you simply add either an acid or an alkali to even it out some.

Most of the products on the market that do this are inexpensive to purchase, and most pool owners check the pH level at least weekly if not more often just to make sure it stays between those two numbers.

Two items can be used if the pH level in your swimming pool gets too high, and they are described here:

Sodium Bisulfate

This product keeps all of the chemicals in your pool at healthy levels. It also stops your pool equipment from becoming corroded, prevents your water from becoming cloudy, and gets rid of microbes and bacteria in the water so it can be safe for you and your family to swim there.

It is also water-soluble and therefore dissolves easily once you place it in the water in your pool. Not to be confused with Sodium hypochlorite – you can read about it here.

Muriatic Acid

This is another ingredient that can lower the pH level and alkalinity in your swimming pool. It is also used to clean the tiles in your pool or spa and get rid of calcium scale deposits, rust, and mold.

While it is a great product for lowering your pH level, you have to be very careful because this is a very caustic product that can burn your skin if the levels aren’t just right. This is why more pool owners use sodium bisulfate to lower their pool’s pH level.

In a swimming pool or spa, the pH and alkaline levels need to be just right to work together to keep the water safe and comfortable.

If anything gets out of whack, it can cause either burning eyes and skin if the levels get too high, or cloudy water and chemicals that just don’t do their job if the levels are too low.

I have a detailed series of articles and guides covering water quality problems. Check them out:

This is why continuously keeping an eye on these levels is one of your main responsibilities as a pool owner.

chemical symbols

How to Use Sodium Bisulfate

While sodium bisulfate is usually preferred over muriatic acid, the latter is often used to clean scale and mold from the walls of swimming pools.

That being said, sodium bisulfate tends to be safer overall and it is super easy to use, these are just a few of the reasons why so many people use it to clean their swimming pools and hot tubs.

Sodium bisulfate is also safer for the environment and is even biodegradable. In fact, the more you learn about both this product and muriatic acid, the more you’ll understand why people choose sodium bisulfate most of the time to keep the pH level in their pool at just the right number.

If you’re wondering how to use sodium bisulfate, it is really very simple. You simply test your pH level to see if it’s within the recommended levels, and if it isn’t, you’ll have to add the sodium bisulfate.

How much you’ll add depends on the size of your pool and the manufacturer’s directions on the package.

In fact, you’ll want to make sure you don’t have too much sodium bisulfate, and many experts recommend adding only three-quarters of what the manufacturer recommends instead of the entire amount. I can confirm this is good practice!

  • For the pH level, the number should be between 7.2 and 7.8, although some experts recommend that it be no higher than 7.6.
  • For the alkaline level, the number should be between 80 and 120 parts per million (ppm).

To reduce the alkaline level, make sure you turn off all the jets in the pool before you add the sodium bisulfate, and add it slowly so that it doesn’t interrupt the pH level in the water.

Regardless of why you’re adding the sodium bisulfate or how much of it you add, it is crucial that you wait a total of six hours before you get back into the pool, and of course, you’ll want to retest the water to make sure the numbers are within the range they’re supposed to be.

This six-hour range is important because it makes sure that the sodium bisulfate does its job and does it right.

Pool & Spa pH Reducer Sodium Bisulfate
Lower the pH of your pool, spa, or hot tub with Pool & Spa pH Reducer!

Another important tip is to decide whether you want to dilute the sodium bisulfate before you put it in the water. Once again, reading the instructions is important because each product is different.

Some require a complete dilution with water before pouring the mixture into your swimming pool, while other manufacturers tell you to place the sodium bisulfate directly into your pool or hot tub.

Whatever the manufacturer recommends is what you should do. Otherwise, when you go to test the water six hours later, it may not be where it should be and in fact, it could be worse.

Did you know that you can use baking soda to raise your pool’s alkalinity? You can – but I’m not a big fan. Read my guide to find out more.

testing pool water pH levels


What are the Benefits of Using Sodium Bisulfate in Your Pool?

The benefits of using sodium bisulfate in your pool include reducing pH levels, preventing scaling and staining on pool surfaces, and improving chlorine efficiency.

How Should You Add Sodium Bisulfate to Your Pool?

Sodium Bisulfate should be added directly to the water, usually in powder form or granules. It’s best to add it after dark when the filter is running so that it mixes evenly throughout the pool.

What Are the Potential Risks of Putting Sodium Bisulfate in a Pool?

Potential risks of putting sodium bisulfate in a pool include irritation to eyes and skin if not handled properly and acid burns if too much is used at once.


Sodium bisulfate is an inexpensive, eco-friendly product that is a must when you’re trying to lower the pH level in your pool or spa. Knowing what the right levels are when it comes to the pH level and alkaline level in your pool or spa is the first step to making sure the numbers stay right where they need to be to keep you and your family safe.

Taking good care of your pool is not difficult or time consuming, so keeping on top of it should never be something you dread.

Last update on 2024-05-19 / Affiliate links / Images from Amazon Product Advertising API

michael keenan author

Author - Michael Keenan

I'm Michael Keenan the owner and creator of the Outdoor Care Guide. I'm a trained horticulturist with over 30 years of experience in pool care, plant care, and landscape care! Seemed like a good idea to share - I think I can make your life easier and save you some time and money!