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Hot Tub Chemicals 101: The Complete Guide for Beginner’s

Ever wondered if hot tub chemicals are actually necessary? Or how do they work? Well, you’re not alone. Most hot tub owners are just as curious, and we’re here to help.

Hot tub chemicals can make your hot tub experience the best it can be, but they can seem really confusing to start with. That’s why we’ve spent time writing this complete guide so you can learn everything you need to know.

We want to demystify chemicals and water care supplies so that you can spend less time asking questions and more time enjoying your hot tub.

Here is the ultimate guide to the common chemicals, supplies, and techniques necessary to maintain your tub.

What Are Hot Tub Chemicals?

All hot tubs share one trait: they need regular cleaning. That’s where the chemicals come in.

Hot tub chemicals are mixtures that remove dead skin cells, body oils, and bacteria from your spa water.

They also calm skin irritations and make long soaks more comfortable. And some chemicals ensure your hot tub stays pH balanced, so you don’t need to refill it as often.

Common Hot Tub Chemicals

There are three main types of hot tub chemicals:

  • Sanitizers
  • Shock treatments (Oxidizers)
  • pH balancers

We’ve put together the information you need about each to make things easier for you.


Sanitizers keep your spa water crystal clear and fresh. These products kill bacteria, algae, and other microbes in your hot tub to keep your water in the best condition possible.

The chemicals most often used to sanitize hot tubs are bromine and chlorine.

Chlorine is probably the sanitizer you’re most familiar with. You’ve seen it in swimming pools as a disinfectant. In hot tubs, chlorine destroys organic substances like body oil.

Bromine works like chlorine in that it destroys organic contaminants like oils and sweat. Yet, unlike chlorine, bromine has a higher pH level—which means it’s gentler on skin and swimwear.

How to Use Sanitizers in a Hot Tub

There is no single correct way to use sanitizers. The product’s instructions will say how often to use it and explain the proper techniques.

But you should know that the directions will always be based on how many gallons of water your hot tub contains. So it helps to have this number on hand before the sanitation process.

If you’re not sure how many gallons are in your hot tub, don’t hesitate to reach out to a professional spa service for help. You can trust that they know how to measure your spa and apply the appropriate amount of product.

After you sanitize the spa, use DPD test strips to make sure that it’s in the suitable range of free chlorine or free bromine.

The Centers for Disease Control recommends that your free chlorine level be at least three ppm. On the other hand, bromine should stay between 3 and 5 ppm. The test strips will tell you whether you’ve hit the mark.

Shock Treatments (Oxidizers)

Like sanitizers, shock treatments or oxidizers improve water clarity and freshness. But, unlike sanitizers, these chemicals are for heavy-duty jobs.

For example, you’ll need an oxidizer to clean your hot tub after a rainstorm, water change, or when tons of people have been in your spa.

And after sanitation, you’ll also need to add an oxidizer. This will remove any residue from your sanitizers.

How to Use Shock Treatment in a Hot Tub

There are two kinds of shock treatments: chlorine and non-chlorine treatments. Chlorine oxidizers are for hot tubs that contain chlorine. And non-chlorine oxidizers should be used after bromine sanitation.

You can purchase these shock treatments in either liquid or granular form.

Using liquid shock treatment is easy. You simply pour it in and let the water warm up.

On the other hand, you must add granular shock in doses according to your hot tub’s requirements. The downside is that granular shocks can be more difficult to dose accurately. Also, using too little won’t get your spa clean, but using too much may irritate your skin.

As you can tell, oxidizers can be difficult sometimes, especially if you don’t have guidance. So it’s best to find an experienced technician to help you during your first attempt.

pH Balancers

These products keep pH levels, alkalinity, and calcium hardness at ideal levels.

As a general guideline, you want your water’s pH to be between 7.2 and 7.8. Spa water beyond this range is hard to sanitize.

The right pH balancers will regulate the alkalinity of your spa water to help the sanitizer work more effectively.

How to Use pH Balancers in a Hot Tub

Before you use pH balancers, you should test the alkalinity of your water. You can do this with testing strips from an at-home kit for hot tubs.

After you use your spa, dip a test strip in the water. Follow the directions on the test strips’ packaging for an accurate reading.

Next, you can add the pH balancer depending on your water’s needs.

Once you’re done, go ahead and test the water again to see if your pH balancer worked. If not, add more of the balancer until your water reaches the perfect alkalinity.

Hot Tub Maintenance

One of the most essential parts of understanding hot tub chemicals is having a routine for using them. Here’s an example of how you can use these chemicals regularly:

  • Sanitize your spa with chlorine or bromine once a week.
  • Follow every sanitation with an oxidizer of your choice.
  • Test the pH levels of your hot tub at least once or twice a week. Add pH balancer when necessary.
  • When not in use, cover the hot tub with a lid. Wipe the hot tub lid monthly to keep dust and leaves from building up.
  • Clean the spa shell every few months to prevent buildup.

Schedule Your Spa Maintenance With Ace Swim and Leisure

All in all, using the three common hot tub chemicals can be a straightforward process. You can always consult professionals like the Ace Swim & Leisure team when in doubt.

We have a large inventory of hot tub manuals for you to choose from so you can be sure your hot tub is getting the best treatments for its design.

We’re also experts on hot tub chemicals and maintenance. Our in-house staff will be happy to answer your questions and help you enjoy all the health benefits that hot tubs have to offer.

And if we discover other ways to help make your hot tub experience better, we’re happy to order parts for you and do routine repairs at your request.

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