What’s the Difference Between Chlorine and Bromine?

Chlorine has been and continues to be the most popular choice for pool and spa sanitization. Most people aren’t sure about chlorine alternatives or how they work. If you’re weighing your options, bromine is another great choice to consider. Wondering about the difference between chlorine and bromine? Read this and we’ll help you decide what’s best for your pool or hot tub.

Chlorine Vs. Bromine

To help define the differences between chlorine and bromine, we’ve broken down the differences into these different categories.


One of the big reasons chlorine is the most popular choice for pool and hot tub owners is because it’s the less expensive choice. Effective and less expensive? What’s not to love! Well for some people, that classic chlorine scent we all associate with pools can be irritating to their eyes and skin. (Or maybe you just don’t love the scent!)


Of course, whatever sanitizer you use, you want to be sure it’s safe and effective. When it comes to sanitizing effectiveness, chlorine and bromine are basically equal. As long as the correct amount of product is added and maintained, they are both effective.

One thing to note is the difference in how these two chemicals work. Chlorine sanitizes water by binding to contaminants. In that process, byproducts call chloramines are produced. It’s because of chloramines that the water has that familiar, lasting smell that we all associate with pools that lingers on your skin and hair after you get out of the water. If someone is chlorine-sensitive, it’s those chloramines that might make their eyes water or your skin to feel itchy. 

Over time, chloramine compounds dilute the sanitizing effect of the chlorine in the water, and a shock treatment is needed to get rid of the chloramines. 

Similarly, compounds called bromamines are created as bromine sanitizes the water. These do not have any lasting smell and are gentler on the skin and eyes. Unlike chloramines, bromamines continue to sanitize and disinfect the water.

Durability to UV Rays and Temperature

How these sanitizers respond to UV rays and water temperature are where they differ the most … and the biggest determiner on whether chlorine or bromine is best for your pool or hot tub.

Bromine is quickly broken down by the sun’s UV rays. To be fair, sunlight destroys chlorine, too, but CYA stabilizes chlorine to protect it. Unfortunately, CYA isn’t able to stabilize bromine. So, if your outdoor pool is in a very sunny area, you’ll be adding bromine a lot, which will become expensive quickly. However, if your pool is in a shady spot, or indoors, bromine can be an ideal choice. In fact, if you have an indoor pool, we recommend bromine, because the smell of chlorine is magnified in an enclosed space. Bromine will be much more comfortable. 

Home Hot Tub

Where bromine really shines is with hot tubs.

It’s much better than chlorine at withstanding high water temperatures. Bromine will be effective in your hot tub for longer periods, while the 102°F water will break down chlorine quickly. So, this is one situation where bromine could actually be the less expensive choice. 

Want an expert opinion on what’s best for your pool or spa? Contact Backyard Oasis! We love serving the Livingston, TX area and can’t wait to help you enjoy your pool and hot tub ownership even more with our high-quality chemical options.