Bromine vs. Chlorine: Learn Which Is Best for Your Pool

Bromine vs. Chlorine – Which is the best choice for your pool? Learn about the benefits of each, how each works, and their pros and cons. Click here for more.

Chlorine and Bromine are both popular choices for swimming pool sanitizers because they’re both effective, fast-acting, and inexpensive to maintain compared to other types of chlorine alternatives. But the two have some important differences you should know about before deciding which one is right for you.

Chlorine is milder to the skin but causes more eye irritation than bromine does. Bromine costs more to maintain but has a less irritating solution than chlorine does. Which one do you prefer? Read on for more information about Bromine vs. Chlorine.

Bromine vs. Chlorine Demystified

Bromine vs. Chlorine: Chlorine Tablets by the Poolside

Bromine is far less potent than chlorine, although it is extremely similar to chlorine in many respects and also has its disinfecting properties. Additionally, it is used to sterilize pools as an alternative for chlorine.

What Are Chlorine and Bromine?

Chlorine and bromine are two chemical elements that are quite close in the Periodic Table of Elements. Both are called Halogens, meaning they are extremely hazardous in their elemental state. Fortunately, the bromine and chlorine we use in our swimming pools are chemical compounds, so they are safe for their disinfecting properties. 

Bromine is considerably too reactive to occur naturally as a free element. It is more frequently found in two compounds: sodium bromide (NaBr) and potassium bromide (KBr), both found in seawater.

What Is the Physical Form of Chlorine and Bromine?

Chlorine is available in a variety of forms, including tablets, sticks, and granular forms. But, by far, the most common for pool owners are chlorine tablets. Compared to liquid chlorine, chlorine tablets slowly dissolve in your swimming pool via floating or automatic feeder, making them the least maintenance-intensive choice.

If you decide to clean your pool using bromine, the process is rather similar to adding chlorine. Bromine is also available in tablet and granule form and is distributed in a similar manner.

“Bromine is best administered through a floating dispenser in tablet form. It does, however, require its own feeder, which may increase the startup costs.”

Matt Giovanisci – pool expert

Bromine vs. Chlorine: What Are the Key Differences?

Both chlorine and bromine work in a similar manner to destroy germs and detoxify pool and spa water. The two primary distinctions between these compounds are: how they affect people and how they react in hot temperatures. 

How Do Both of Them Work?

Bromine vs. Chlorine: Chlorine-Bromine Float

When chlorine is added to a swimming pool, chlorine molecules immediately begin fighting pollutants through oxidation.  Chlorine steals electrons from whatever junk is there in your pool, altering its molecular structure in the process.

In the course of this chemical reaction, chlorine produces a waste product known as chloramines. If you’ve ever wondered where the noxious chlorine odor comes from, now you know. Chloramines are responsible for the itchy, dry skin and a smelly odor that swimmers experience we typically associated as the chemical itself.

Bromine, on the other hand, sterilizes pools of water through the process known as ionization. It’s the same fundamental concept: bromine sticks to bacteria to break away the chemical bond that holds the bacteria together.

Moreover, bromine has a lower pH level than chlorine, so maintaining your optimal pool chemistry is going to be easy using this sanitizing method. 

Because bromine has a lower pH than chlorine, balancing the chemistry of your water will be a breeze using this infecting method.

How Much Chlorine and Bromine to Use?

Another key difference between chlorine and bromine is the amount of chemical necessary to perform the same function – which is to sterilize. Because of the chemical processes of each, the bottom line is more bromine is needed to sanitize the same amount of water.

No matter what we tell you here, it’s important that you read and follow the manufacturer’s instructions before adding the pool chemicals to the water.

Chemical formulas differ from one another, and each pool/spa has its unique set of requirements. Once you’ve followed the instructions and tested the water, you’ll be able to determine whether or not more disinfection is necessary.

Chlorine1-3 ppm
Bromine3-5 ppm

How Fast They Kill

Chlorine is a highly reactive chemical. It swiftly rips through the filth in your pool and then is finished. Bromine is a little laid back than chlorine, but its sanitizing power lasts far longer than chlorine.

It’s quite like the story of the Tortoise and the Hare. Both will cross the finish line but at their own speed.

How Swimmers React to Them

Bromine vs. Chlorine: Athlete Swimmer in Pool

The good news is that these chemicals are entirely safe for humans when used in the recommended amounts and according to manufacturer instructions. You’re expecting the snag, right? There is one, and that is that each individual reacts differently to these chemicals.

For example, it’s hard for me to open my eyes underwater in a pool, no matter what pool I was swimming in. My eyes are sensitive. Needless to say, it’s quite a pity that I can’t open my eyes underwater like some of my friends does. 

Chlorine can be particularly harsh for people with sensitive skin and eyes (like me). When chlorine sterilizes the pool water, it leaves a byproduct called chloramines. This could irritate your skin, eyes, and produce a distinct “chlorine” smell. 

On the other hand, bromine is an excellent option for people sensitive to chlorine because it’s kinder on the skin. It is far less abrasive than chlorine, and its odor is not as harsh and chemical-smelling as chlorine. It also does not have the same risk of triggering asthma problems due to chloramines. 

What’s Best for You?

Pool or spa water can be disinfected and oxidized with either bromine or chlorine. Bromine is more effective in high-temperature environments and is gentler on the skin. In contrast, chlorine is less expensive, lasts longer, and does not break down as quickly when exposed to ultraviolet light, especially when combined with cyanuric acid.

In the end, it all comes down to your own research and personal preference, and the location of your pool. 

  • Want to save more on pool chemicals? Go with chlorine.
  • Have sensitive skin or asthma? Bromine might do the trick.
  • Situating in a very hot climate? Bromine might be the best option.
  • Too much sunlight in your pool area? Chlorine is probably the good choice.


Hopefully, you now have a better understanding of your pool and spa sanitizing alternatives. Whichever sanitizer you choose, it’s important to remember that the fundamentals of pool care, and maintaining proper pool chemistry are the key to a sparkling healthy pool that’s safe for all swimmers.

The following are some tips to help you maintain your swimming pool in the most efficient and safe manner. Our complete guide can be found here, and some of it has been added below.

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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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