Should I use Bromine or Chlorine in my Hot Tub?

 

Let’s face it, there is no better way to relax than in a Hot Tub in your backyard. Whether it is summer or winter, they are just perfect all year round. However, if you want to ensure your water is healthy and clean then regular maintenance is a must! This is primarily done through the use of disinfectants.

You already know that Chlorine and Bromine are the two most popular disinfectants for the job. Which one suits you or which one is best for your setup is the real question. Since both chlorine and bromine have their pros and cons, how4 they work for you depends on your preferences and needs.

In this article, I will break down the pros and cons of both these chemicals so that you can make your own informed decision based on your personal requirements.

How Chlorine Works in Your Hot Tub

You’ve probably heard of chlorine—it’s the go-to sanitizer for hot tubs, pools, and even drinking water. But how exactly does it keep your hot tub clean?

When added to water, chlorine undergoes a chemical reaction that kills bacteria and other contaminants. Over time, the solution breaks down, continuing to disinfect as it does. Available in tablets, liquids, and granules, all chlorine products serve the same purpose: keeping yo

How Bromine Works in Your Hot Tub

Bromine is the top alternative to chlorine, especially for hot tub owners who prefer a sanitizer that works better in warm water.

While bromine and chlorine both eliminate bacteria and contaminants, they break down differently in the water. Like chlorine, bromine comes in tablets and liquids (never in raw form). Liquid bromine is always diluted with water for safety, as it can be harsh on skin and eyes.

Though it works similarly to chlorine, bromine has a milder odor and a different chemical degradation process, making it a popular choice for hot tubs.

Pros & Cons of Using Bromine

Pros:

• No strong chemical smell
• Gentler on the eyes and skin than chlorine
• Works well as a disinfectant and algaecide
• Acts as an oxidizing agent to break down contaminants
• Ideal for hot tubs due to its stability in warm water
• Safe for use with vinyl, concrete, and fiberglass hot tubs

Cons:

• More expensive than chlorine
• Weaker oxidation power compared to chlorine
• Not suitable for people with chlorine allergies
• Breaks down quickly in sunlight, making it less effective for outdoor pools without a cover

Bromine is a great choice for hot tub sanitation, especially for those who want a gentler, odor-free alternative to chlorine. However, it’s important to consider its higher cost and sensitivity to sunlight before making the switch.

Shocking Procedure

Chlorine and bromine work differently to disinfect hot tub water. Chlorine acts fast, killing bacteria immediately upon contact. Because it breaks down quickly, it needs to be added about every two days.

Bromine works more slowly but lasts longer. It remains active even after killing bacteria, so you only need to add it once a week.

Application

Chlorine comes in granules, liquid, or tablets. Granules and liquid can be poured directly into the water, while tablets are placed in a floating dispenser to maintain levels.

Bromine is best used with a floating or cartridge dispenser, which can increase the initial cost. However, one application can last up to a week, whereas chlorine needs to be added every other day.

Cost Comparison

• Chlorine: A 20,000-gallon hot tub used year-round costs about $600 per year. If using tablets, a floating dispenser costs around $20.
• Bromine: The same hot tub would cost around $1,000 per year for bromine. Additionally, a bromine feeder system may cost between $150 and $400.

Health Considerations

• Bromine is gentler on skin and eyes, making it a better option for sensitive users.
• Chlorine allergies? Unfortunately, bromine won’t work either, as it contains chlorine compounds. In that case, alternatives like peroxide-based systems or silver/copper ion generators may be needed.
• Bromine has less odor, but it can be harder to rinse off after soaking.

Performance in High Temperatures

• Bromine is more stable at hot tub temperatures (above 75°F).
• Chlorine works better in cooler water (up to 65°F), making it ideal for unheated pools.

Water Clarity

• Chlorine keeps water crystal clear by breaking down bacteria, body oils, and organic matter.
• Bromine has a lower pH, which makes it less effective at removing oils. This can cause cloudy water, requiring occasional chlorine shocks to maintain clarity.

 

Conclusion

Both chlorine and bromine are excellent options for keeping your hot tub water clean. Their effectiveness should not be questioned but of course each is suited to its own environment. 

When it comes to choosing between chlorine and bromine as a disinfectant for your hot tub, you should consider not only the cost, but also the ease of use and safety concerns. Hopefully, you now know how each of them work and how to add them to your system. 

Feel free to reach out if you have any questions or need any help in your DIY hot tub journey! Until next time, 

Happy Hot Tubbin!

 

Can I Help You?

If I can help you in any way I would love to hear from you. You can get in touch using the form below.

Thanks - Andi

 

Hi, Andi here. I own Buildahottub.com and also write all of the articles and info pages on the site. Some years back now, I built my own hot tub but struggled to find the information I needed. So, once my tub was complete, I started this website to help others in their own pursuit of hot tub and plunge pools DIY building information.

Fast forward to 2025, I've helped over 1400+ DIY customers just like you all over the world build hot tubs and pools. Have a good look around the site, there are lots of resources here. Please do get in touch if I can help you. - Cheers, Andi