Chlorine Vs. Bromine? Tub Has Ozonator...

[Laenini]

We got our first hot tub about 2 weeks ago and so far are greatly enjoying it! We have had an above ground pool for about a year and use the BBB system in the pool to great success! Naturally, I assumed I would just follow the same BBB principles in the hot tub since they had been so successful for me in the pool, and that is pretty much what I have been doing the last 2 weeks. I've also been doing lots of message board reading though this forum and over at www.troublefreepool.com about spa care and water chemistry issues. A few things have finally clicked for me and I am starting to do some rethinking.

My spa has an ozonator and it seems to me based on the recent readings I have done that an ozonator can be used in either a chlorine spa (like I am running right now) or a bromine spa (what I am thinking of converting to). But, in a chlorine spa an ozonator increases the rate of breakdown of the chlorine (active sanitizer) and therefor the spa might require more frequent additions of chlorine to keep it appropriately sanitized when the ozonator is running. While in a bromine spa the ozonator actually helps to convert the bromide reserve into active bromine sanitizer? So while that may mean the bromide reserve is depleted more often and water changes may then need to be more frequent, the ozonator helps keep a steady supply of active bromine sanitizer being formed in the tub. So ultimately an ozonator actually complements a bromine spa to a greater degree than it might a chlorine spa?

Am I understanding this all correctly? Because if I am, I think I will covert over to a bromine system. Advice anyone?

Thanks!!

[Jim C.]

Your understanding is pretty much correct. I think you will like the bromine with the ozone. I do not think going with Bromine will require any more frequent water changes, though. I'm not sure I understand where you were going there.

Ozone as an activator of the bromide (from the little packet of salt that you add) is a great spa system.

I also use a small bromine tab floater to constantly add to the bromide reserve and generate some more bromine (in addition to what the ozone generates). I do not totally fill the floater with tabs or the Bromine level gets too high. I add 1 tab a week to the floater. This ends up being a very low maintenance system, which I like.

[Nitro]

Yes, you are understanding it correctly. However, to put things into perspective. An ozonator will increase your Chlorine Demand from 25% to around 50%. That means if you shock to 10 ppm FC, without use, it will last 3 days with an Ozonator. Without an ozonator it will last a week. So you figure you will be adding Chlorine twice as often with an Ozonator.

I would say if you plan on using the tub often (more than once a week), try Chlorine. You'll be adding Chlorine after every soak anyway. However, if you only plan on using the tub once a week or less, go with Bromine. Also, if you start with Chlorine and you find you don't like it, you can always switch to Bromine. However, if you start with Bromine, you can't switch to Chlorine without doing a water change.

Food for thought.

[Laenini]

Actually, we have been using the tub very heavily in the 2 weeks we've had it. We have 2 college age kids who have been in and out of the tub with their dates and friends. Even before we got the new tub we had gotten into the habbit of having company over most weekends to swim in our pool with us, so there have been plenty of people in and out of the new tub. I've been adding chlorine after soaks and also using MPS shock when entertaining, but twice now I've gone out to test the hot tub and found the TC at 0 when I wasn't expecting it to have dropped so low at all! So I am thinking with the heavy usage, a bromine system that works with the ozonator to basically "feed" bromine sanitizer into the tub during each filter cycle might be the way for us to go.

[Nitro]

If your FC was zero, it just means you're not using enough Chlorine. I'd say you need to DOUBLE the amount of Chlorine/MPS you're using. Adding the correct amount of Chlorine does have a learning curve, especially with high bather loads. Just don't be affraid to add a ton of Chlorine/MPS.

OTOH, the fact you have an ozonator, high bather loads and kids using the tub (whom I assume don't add Chlorine themselves), Bromine may be the way to go in your case.

[Laenini]

Well, I did go ahead and convert over to bromine. I used Sodium Bromide to start my reserve, my ozonator is operating, and I have a floater with bromine tabs in it. I know to shock once weekly with chlorine and to wait for the bromine level to drop below 10 before using the tub after shocking. I have one question though that I am unsure about. Do I still add anything after soaks now with the bromine system? If so, what do I add and how much of it do I put in?

Thanks for the much needed advice!

[Nitro]

Well, I did go ahead and convert over to bromine. I used Sodium Bromide to start my reserve, my ozonator is operating, and I have a floater with bromine tabs in it. I know to shock once weekly with chlorine and to wait for the bromine level to drop below 10 before using the tub after shocking. I have one question though that I am unsure about. Do I still add anything after soaks now with the bromine system? If so, what do I add and how much of it do I put in?

If you have a floater you shouldn't need to. However, you should keep an eye on your Bromine level before you use the tub each time to make sure you have the floater adjusted correctly.

Here is a great writeup on using Bromine.

[Tomab]

An ozonator will increase your Chlorine Demand from 25% to around 50%. That means if you shock to 10 ppm FC, without use, it will last 3 days with an Ozonator. Without an ozonator it will last a week. So you figure you will be adding Chlorine twice as often with an Ozonator.

I thought that having an ozonator was to reduce the load on chlorine but this suggests the opposite.

What then is the purpose or good reason to use an ozonator along with chlorine? Please straighten me out on this.

[Nitro]

I thought that having an ozonator was to reduce the load on chlorine but this suggests the opposite.

What then is the purpose or good reason to use an ozonator along with chlorine? Please straighten me out on this.

I should rephrase. An Ozonator will increase the IDLE Chlorine Demand. That means when the tub is not being used, the ozonator has little to do. However, it will outgas Chlorine, lowering your FC faster. OTOH, after the tub is used the ozonator will HELP oxidize bather waste, therefore saving FC.

What does all that mean? It means an ozonator will increase your CD when not using the tub, but will help keep CD lower when you are using the tub.

Make sense?

[Tomab]

I thought that having an ozonator was to reduce the load on chlorine but this suggests the opposite.

What then is the purpose or good reason to use an ozonator along with chlorine? Please straighten me out on this.

I should rephrase. An Ozonator will increase the IDLE Chlorine Demand. That means when the tub is not being used, the ozonator has little to do. However, it will outgas Chlorine, lowering your FC faster. OTOH, after the tub is used the ozonator will HELP oxidize bather waste, therefore saving FC.

What does all that mean? It means an ozonator will increase your CD when not using the tub, but will help keep CD lower when you are using the tub.

Make sense?

Now it does. Thanks.

I was just making sure. I'm getting an ozonator installed on my tub next week...The one the dealer forgot to order from the factory....another story. I needed to know if it is the right choice to have it installed while using chlorine.

While I'm at it Nitro, I want to say thanks for all your info about the bleach method along with all the other information you and everyone else provides on this forum. I've been doing the bleach for about 3 months and it's working great.

Thanks again,

Tomab

[Nitro]

Now it does. Thanks.

I was just making sure. I'm getting an ozonator installed on my tub next week...The one the dealer forgot to order from the factory....another story. I needed to know if it is the right choice to have it installed while using chlorine.

While I'm at it Nitro, I want to say thanks for all your info about the bleach method along with all the other information you and everyone else provides on this forum. I've been doing the bleach for about 3 months and it's working great.

Thanks again,

Tomab

You're quite welcome. Glad it's working out for you.

[SJ Hart]

Well, I did go ahead and convert over to bromine. I used Sodium Bromide to start my reserve, my ozonator is operating, and I have a floater with bromine tabs in it. I know to shock once weekly with chlorine and to wait for the bromine level to drop below 10 before using the tub after shocking. I have one question though that I am unsure about. Do I still add anything after soaks now with the bromine system? If so, what do I add and how much of it do I put in?

Thanks for the much needed advice!

Do you shock with chlorine when using bromine???

[Peteyboy]

I would like to add that if you are using Bromine tablets to keep a close eye on the pH & alkalinity. Bromine tabs are about a 3 on the pH scale and can drop pH very fast.

[Laenini]

Well, I did go ahead and convert over to bromine. I used Sodium Bromide to start my reserve, my ozonator is operating, and I have a floater with bromine tabs in it. I know to shock once weekly with chlorine and to wait for the bromine level to drop below 10 before using the tub after shocking. I have one question though that I am unsure about. Do I still add anything after soaks now with the bromine system? If so, what do I add and how much of it do I put in?

Thanks for the much needed advice!

Do you shock with chlorine when using bromine???

Well, I am a newb but my understanding is that once weekly you do need to shock a bromine tub. I believe you can use either chlorine or MPS shock. The chlorine/MPS shock functions to oxidize sodium bromide from your reserve into your active sanitizer, hypobromous acid. The shocking process just converts a greater concentration of the bromide ions into the hypobromous acid to ensure the spa is cleared of all organic matter on a regular basis.

In my chlorine sanitized swimming pool, I haven't had to shock yet this summer. But in the pool I can test for combined chloramines which if present indicate the presence of organic matter. Shocking by adding a high level of chlorine breaks down down those organics. My pool has consistantly tested negative for combined chloramines all summer, thus there has been no need to shock it.

As far as I know, there isn't a similar test for a bromine spa to check if the spa needs to be shocked or not. So I think the practice is to play it safe and routinely shock a bromine spa once weekly.

Some of you more experienced guys please chime in if I explained any of this wrong?

And BTW, I seem to be running much more stable sanitizer levels since converting to the bromine. So far I am happy with the switch!

[SJ Hart]

Guess I shock using MPS once/twice per week. I always assumed since you couldn't switch from chlorine to bromine without emptying your spa, that that meant you shouldn't use chlorine to shock. However, I believe that bromine tabs have chlorine in them? I recently switched to bromine, so I'm still learning! When testing bromine using my test kit (Taylor), it has a test for FC and CC (for chlorine, but seems to work for bromine). Not sure if the CC test means anything when using bromine?

[Tomab]

I always assumed since you couldn't switch from chlorine to bromine without emptying your spa, that that meant you shouldn't use chlorine to shock.

I think it is the other way around...meaning you can go from chlorine to bromine but NOT from bromine to chlorine without doing a drain as quoting from Nitro.

Also, if you start with Chlorine and you find you don't like it, you can always switch to Bromine. However, if you start with Bromine, you can't switch to Chlorine without doing a water change.

[Nitro]

I always assumed since you couldn't switch from chlorine to bromine without emptying your spa, that that meant you shouldn't use chlorine to shock.

I think it is the other way around...meaning you can go from chlorine to bromine but NOT from bromine to chlorine without doing a drain as quoting from Nitro.

Also, if you start with Chlorine and you find you don't like it, you can always switch to Bromine. However, if you start with Bromine, you can't switch to Chlorine without doing a water change.

Correct, you can switch to Bromine from Chlorine, by just adding Bromine reserve. However, you can't switch to Chlorine from Bromine, because any Chlorine you add to the tub, will "recharge" the Bromine. Which BTW, is what you want to do in a Bromine tub.

[tony]

I always assumed since you couldn't switch from chlorine to bromine without emptying your spa, that that meant you shouldn't use chlorine to shock.

I think it is the other way around...meaning you can go from chlorine to bromine but NOT from bromine to chlorine without doing a drain as quoting from Nitro.

Also, if you start with Chlorine and you find you don't like it, you can always switch to Bromine. However, if you start with Bromine, you can't switch to Chlorine without doing a water change.

Correct, you can switch to Bromine from Chlorine, by just adding Bromine reserve. However, you can't switch to Chlorine from Bromine, because any Chlorine you add to the tub, will "recharge" the Bromine. Which BTW, is what you want to do in a Bromine tub.

Bleach is actually a good product to shock your bromine tub. Its pH is higher both dichlor and MPS which will help with the very low pH of bromine.

[Nitro]

Bleach is actually a good product to shock your bromine tub. Its pH is higher both dichlor and MPS which will help with the very low pH of bromine.

Not to mention it's cheap.