Bromine or Chlorine? The Best Sanitizer for Your Hot Tub

clean hot tub water

The water in your hot tub should be inviting and safe to use. But the key to keep it clean and clear is a sanitizer. A hot tub sanitizer helps remove bacteria, contaminants, and other things you don’t want in your water. Without a product like bromine or chlorine, the warm water of your spa will become a breeding ground for things like algae and bacteria.

But which sanitizer should you use — chlorine or bromine?

There are pros and cons to both chlorine and bromine. For some, it might be a personal preference. For others, it might depend on the filtration system of the hot tub. Be sure to reference the owner’s manual for your hot tub and follow the manufacturer’s recommendations. Some systems work best with chlorine. 

Keep reading to learn whether you should use bromine or chlorine in your hot tub.

hot tub chlorine bromine
Chlorine for your hot tub can come in tablets or as granules. Be sure to test your hot tub water before adding chemicals.

Chlorine for Your Hot Tub

Chlorine is a naturally occurring chemical element that is found in sea water and on land. Most people know chlorine as a component of the household product, bleach. But chlorine is also used as a sanitizer for your hot tub.

How does chlorine work in your hot tub? 

It acts as an oxidizer. In a way, the chlorine acts as an army — invading contaminants and then destroying them. As the chlorine does its job, it will produce chloramines. This waste product can give your hot tub water the smell and stinging sensation that some people associate with chlorine.

However, some hot tub filtration systems remove chloramines from the water. 

How often do you add chlorine to your hot tub? 

You’ll need to put chlorine in your hot tub about once a week, depending on how often and how many people use it. Your chlorine levels should be between 1.5 and 3.0 ppm. 

Hot tub owners who use chlorine might also have to shock the water.

What kind of chlorine to use in a hot tub?

Hot tub owners should look for dichlor chlorine granules. While there are tablets and floaters, these products do need to be monitored and removed from the water once it reaches the proper levels. 

It’s crucial not to use beach or trichlor chlorine, which is used by pool owners. These products can damage the components of your hot tub.

bromine floater
If you choose to use bromine in your hot tub, you will need a floating dispenser. Bromine takes longer to dissolve than chlorine.

Bromine for Your Hot Tub

Bromine is an alternative to chlorine and is used to keep hot tub water clean and clear. Like chlorine, it’s a chemical element in the Halogen family. 

Unlike chlorine, though, bromine works by ionizing the contaminants in hot tub water. It breaks up the particles in the water by forcing apart the chemical bonds. The waste product is called bromamines. Bromamines are formed when bromine combines with ammonia. 

Many people choose bromine because it is considered to be less irritating to the skin and eyes. However, it’s important to consider that bromine takes longer to dissolve and can “stick” to swimwear and clothes longer. People who soak in a bromine hot tub will need to rinse off longer after getting out as the sanitizer can cause itchiness and red eyes.

How often do you add bromine to your spa?

Bromine takes longer to dissolve, staying in your spa water for a longer period of time than chlorine. But your hot tub will also need a “bromine reserve” for proper sanitation.

Depending on how often and how many people use the hot tub, you will need to add bromine every few days.

What kind of bromine to use?

You can buy brominating granules for your spa but most people choose to use bromine tablets. The tablets are added to your hot tub water with a floater as bromine stays in the water longer than chlorine.

When adding bromine to your spa water, your sanitation level should be between 3 and 5 ppm.

Best Sanitizer for Your Hot Tub

Regular water care for your hot tub includes adding a sanitizer — chlorine or bromine.

How do you pick the best product for you and your hot tub? Consider the pros of each product.

Pros for Chlorine

  • Less expensive than bromine
  • Kills contaminants more quickly
  • Less sensitive to sunlight. If you have an outdoor hot tub without a cover, you should use chlorine. 
  • Dissolves more quickly, allowing you to use your hot tub sooner after treating the water.

Pros for Bromine

  • Bromine is more stable at a higher temperature, allowing it to kill contaminants when your water is at 104 degrees
  • Stays in the water longer than chlorine
  • Requires less frequent testing

Conclusion: Chlorine and bromine are both effective at keeping your hot tub water clean. The best sanitizer will work with your hot tub filter system while complementing your lifestyle.