When you type “bromine or chlorine for a hot tub” into Google, you get about 205,000 search results in just half a second. The age-old debate between chlorine and bromine for hot tubs continues. Is one better than the other? Should you consider using bromine tablets? And if so, what do you have to gain?

Both chlorine and bromine are popular hot tub sanitizers but they get the job done differently. Let’s look at the pro’s and con’s of each.

1. Maintenance

Chlorine hot tubs require much more active maintenance and attention than bromine hot tubs. Without constant attention, chlorine hot tubs are much more likely to turn cloudy or green.

In addition, pH levels can often rise quickly in hot tubs and bromine is less exposed to these pH fluctuations. Chlorine, on the other hand, can’t handle large swings as efficiently as bromine, requiring frequent attention.

2. Efficiency And Effectiveness

Chlorine acts faster than bromine but dissipates quicker because it breaks down faster in high water temperatures. Once all the chlorine is used up, however, it requires frequent additions. On the other hand, bromine tablets take longer to dissolve, and once the active bromine has killed off unwanted organisms, dormant bromine salt remains behind, which can be reactivated into active bromine over and over. This makes bromine an active sanitizer for a longer period of time.

3. Water Temperature

The sweet spot for chlorine is between about 65 and 99 degrees. It quickly turns into vapor at around 100 degrees. While bromine is less effective at temperatures below 75 degrees, it thrives in hot water environments, especially over 100 degrees.

Hot tubs are, well, hot, small and typically have more people in them at the same time relative to their size. It is said that “4 people soaking in a typical hot tub equates to approximately 160 people in a backyard swimming pool due to chemical demands”. These factors make bathers perspire more, resulting in an increased amount of sweat and oils, and higher demand for sanitization. Bromine is better suited than chlorine to handle the buildup of these waste materials in hot water.

4. Cost

Many people choose chlorine because it’s less expensive at first. Although bromine can cost 20% or more than chlorine, it can stay longer in your water due to its ability to be reactivated after it has killed all the bacteria. This means that in the long run, you’ll use less bromine and hence, will pay less.

If you live in an area that gets a lot of sunshine all year round, costs related to sun protection may also play a role in your decision. Chlorine can be protected from the sun if you add the right amount of stabilizer to it. Bromine is broken down by the sun faster, requiring you to add bromine to compensate for the UV breakdown. However, when bromine is broken down by the sun’s UV, it leaves behind dormant bromine salt (sodium bromide), which can be reactivated by additional bromine or non-chlorine shock to perform additional sanitization.

5. Personal Considerations

Chlorine has been the subject of many jokes and urban legends. Some people with sensitive skin may find chlorine to be more irritating than bromine. Experts say that bromine protects the eyes and skin better, and emits less odor than chlorine.


For Chemistry Lovers

We’ve asked our chemistry expert to give his pick between bromine and chlorine for hot tubs.

This is what he had to say:

Bromine! It remains effective in a wider range of pH levels (7.0 – 8.4) than chlorine (7.4 – 7.8), and therefore, it can better protect your water from bacteria and viruses. Also, bromine in itself is a strong sanitizer. At a high pH level of 7.8, only about 25% of chlorine is active, but bromine remains efficient. And its byproducts, bromamines (a combined substance), produce their own sanitizing action, making bromine an even more powerful bacteria and virus killer. Add to that, that bromine already in your water can be reactivated using potassium monopersulfate after it has killed the bacteria. Reactivated bromine means less chemical use and bigger cost savings for you in the long run.

Using Bromine Is Easy

Using bromine tablets in your hot tub is simple:

No need to drain your hot tub: you can get started with bromine right away. There’s no need to interrupt your hot tub usage for several days to drain and refill your hot tub. This also means that if you change your mind later and want to switch back to chlorine, you can easily do so.

Get the chemicals you need: To help provide the healthiest water care option and further simplify hot tub care, we will send you the chemicals you need at the time of shipping so you can start using bromine in your hot tub.