Chlorine Vs. Bromine: What's The Right Hot Tub Sanitizer For You?

So you obviously need a sanitizer in your hot tub. The question is, which one should you use? Chlorine or bromine? And should you use tablets or granules? Choosing the best sanitizer for your spa is easy once you know a little bit about each type and how to add them to your hot tub.

Creators & Guests

Host

Matt Giovanisci

Founder of SwimUniversity.com

What is Hot Tubs 101?

A podcast for hot tub owners covering hot tub maintenance and water chemistry.

Matt Giovanisci: 00:00

Everyone, and welcome to hot tubs 101 by Swim University, where we help you keep your hot tub clean and clear all year. My name is Matt, and I'm the founder of swimuniversity.com. And on this episode, we're talking about chlorine versus bromine and which one is the right hot tub sanitizer for you. Let's dive in. Real quick, if you want more help taking care of your hot tub, be sure to grab our free hot tub cheat sheet at swimu.com/spa sheet.

Matt Giovanisci: 00:40

So, obviously, you need a sanitizer in your hot tub. The question is, which one should you use? Should you use chlorine or or bromine? And should you use tablets or granules? Choosing the best sanitizer for your spa is easy once you know a little bit about each type and how to add them to your hot tub.

Matt Giovanisci: 00:58

So first, what's the difference between chlorine and bromine? While chlorine is the most common sanitizer for swimming pools, bromine is used more often in hot tubs. While they both kill bacteria, the biggest difference is how they kill bacteria. So chlorine oxidizes contaminants, invading the particles and destroying them from the inside out. And once the chlorine dissipates, it's it's turned into a waste product called a chloramine.

Matt Giovanisci: 01:27

Now this causes that chlorine smell and can actually cause your eyes to burn. It also reduces the sanitizer's effectiveness. So to keep chloramines at bay, you'll need to add chlorine on a regular basis, usually at least once a week. And if it gets really really bad, you'll need to shock your hot tub. Bromine, on the other hand, ionizes contaminants, attacking and forcing the chemical bonds of the pollutants to break apart.

Matt Giovanisci: 01:55

But unlike chlorine, lot of of the bromine remains active in the water, even after killing or even after combining with those contaminants and killing them. And you won't get that chlorine smell that you get with, you know, chlorine, obviously. Another difference between these two chemicals is their effectiveness. Now chlorine kills contaminants more quickly than bromine does. Brom bromine is not as reactive as chlorine, so it kills more slowly.

Matt Giovanisci: 02:22

But bromine has a lower pH than chlorine, so it can keep your overall water chemistry more balanced. Next is the chemical stability. Now while chlorine may work more quickly, bromine is more stable than chlorine, especially in warm water. Chlorine dissipates more quickly than bromine, so it needs to be replaced more often. And bromine kills bacteria in your spa for a longer period of time than chlorine.

Matt Giovanisci: 02:49

However, ultraviolet or UV light destroys bromine more quickly than chlorine. So if you have an outdoor hot tub, you wanna make sure that you're always using a hot tub cover. Now that you know a little bit about each one of these chemicals and what makes them different, What's the right dosage amount for each one? So the ideal chlorine level is 1 part per million to 3 parts per million. So, 1 to 3.

Matt Giovanisci: 03:14

And 3 is really the ideal. The ideal level for bromine is a bit higher from 3 to 5 parts per million with 5 parts per million being ideal. Now, if you end up with too much chlorine or too much bromine in your hot tub, don't worry, you don't have to completely start over with fresh water. You can just let the chemicals dissipate over time. Just give it just keep the hot tub cover off, and it will go away.

Matt Giovanisci: 03:38

Now one thing to keep in mind is you'll likely need a larger dose of bromine than chlorine to sanitize your hot tub. And bromine costs more than chlorine. But because you don't have to use it as often, it actually might even out. And a lot depends on the size of your hot tub and how well you keep the water clean and balanced. So whether you choose chlorine or bromine, here's some things not to do.

Matt Giovanisci: 04:04

Don't mix them together in the water or in their dry chemical state. This can cause a dangerous chemical reaction. And if you're gonna switch from one to the other, I would recommend draining and cleaning out your hot tub and doing a line flush, and then refilling the fresh water and starting over. Do not store them next to each other. Even in separate containers, the fumes they can give off can combine and become combustible.

Matt Giovanisci: 04:29

And do not use the same feeder or floater for both, whether you use chlorine or bromine tablets or granules. Some of the chemical remnants can react with each other. And then finally, what's the difference between the granules and the tablets? Now whether you use chlorine or bromine, if you know how to use a measuring cup, then you know how to add granules to your hot tub. You do is you figure out your hot tub's volume and how much water it holds.

Matt Giovanisci: 04:58

You wanna turn your hot tub on and read the instructions on the chlorine or bromine container carefully. Measure the amount of chlorine or bromine based on your hot tub's volume. Then you pour the granules slowly and directly into the hot tub. You allow it to circulate for 20 minutes and allow the sanitizer to disperse, and then test the water again to make sure that your sanitizer is at the right level. Okay.

Matt Giovanisci: 05:21

Super simple. But how do you add chlorine and bromine tablets? Well, the good news about tablets is that you don't have to add these as often as you add the granules. Number 1 is you wanna read the instructions on your tablet's container carefully, as always. 2, place the recommended number of tablets, usually they're 1 inch tablets, into a feeder, or it's called a floater, a float, a dispenser, a chlorinator, or a brominator.

Matt Giovanisci: 05:45

They go by many names. Adjust that feeder if it's adjustable. There usually is a, you know, a thing that spins at the bottom that just creates a larger opening. And that controls, how much of the sanitizer gets released. You wanna hold the feed feeder under the hot tub water for a few seconds to push all the air out.

Matt Giovanisci: 06:04

And then test your water over the next few days to ensure that you have the proper sanitizer levels. You're gonna have to adjust it a bit over time. Now remember, no matter how well you man you maintain those sanitizer levels, you still have to drain and clean your hot tub every once in a while, ideally every 3 to 4 months. And whether or not you choose corn or bromine, it's okay to change your mind. That's the that's the beauty.

Matt Giovanisci: 06:28

Since you'll be changing the water and deep cleaning your hot tub every few months anyway, you can always decide at this point if you don't like the sanitizer you're using to switch to the other one. Again, just do not mix the 2 together and regularly test your sanitizer levels. That's it. Alright? Now remember, if you need more help with hot tub maintenance, grab our free hot tub cheat sheet at swimu.com/spa sheet.

Matt Giovanisci: 06:51

And if you found this episode helpful, subscribe for more hot tub maintenance tips on your favorite podcasting app. And when you do, leave us a review because your review helps support the show and helps more hot tub owners just like you find it. That's it. Thanks again, and happy soaking.