How do I use Bromine in my spa (or pool)?

Status
Not open for further replies.

wardnency12

New member
Jun 3, 2010
1
My Friend is using bromine in his hot tub. It has a very strong odor and added extra bromine and it still registers very low on the bromine test strip. He is not able to use it because he can’t stand the smell. He had the water analyzed and it showed everything was good except the bromine level.
 
Apr 30, 2010
17
My bromine test strips were completely inaccurate, totally useless. The Bromine was very high but strips still read very low. Perhaps the pool shop may not be doing an accurate test either? Get a good test kit and try again. When bromine is right, there is very little smell.
Larry
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,083
San Rafael, CA USA
Welcome to TFP! :wave:

Yes, it applies, but bromine is usually not as suitable for pools since it cannot be protected from breakdown from sunlight as readily and is usually a lot more expensive. There have been a few reports from people using bromine who didn't find the daily loss to be too bad, but others have noted the much higher cost. The disinfection by-products from bromine can be worse than those from chlorine. So overall, chlorine is what is recommended for pools while for spas with the much lower water volume either is recommended.

Do note that once you turn your pool into a bromine pool, you cannot go back to chlorine without a nearly complete water change.

Was there any particular reason why you were interested in bromine rather than chlorine?
 

TJ

New member
Aug 22, 2009
2
chem geek said:
Welcome to TFP! :wave:

Yes, it applies, but bromine is usually not as suitable for pools since it cannot be protected from breakdown from sunlight as readily and is usually a lot more expensive. There have been a few reports from people using bromine who didn't find the daily loss to be too bad, but others have noted the much higher cost. The disinfection by-products from bromine can be worse than those from chlorine. So overall, chlorine is what is recommended for pools while for spas with the much lower water volume either is recommended.

Do note that once you turn your pool into a bromine pool, you cannot go back to chlorine without a nearly complete water change.

Was there any particular reason why you were interested in bromine rather than chlorine?
We were told that bromine is not as harsh on your skin as chlorine. my husband is very sensitive to chlorine, so we've been trying bromine. we were also told that bromine stays present in the water longer then chlorine (once you get the base level adjusted). however, I can't seem to get the bromine level high enough. I've been checking the PH and it's always 7.2 or 7.6, We do have a thermal pool cover, hope that keeps the chemicals in place longer.
 
  • Like
Reactions: Jenn1215

Vandergraff

Well-known member
Jun 22, 2010
84
I am trying to use the 3-step system. To set the bromine reserve I used 'brominating granules' which I assumed would be similar to crushed brominating tablets. The ingredients are sodium dichloro-s-triazinetrione 82.5%, sodium bromide 14.7% other ingredients 2.8%. I am using brominating tablets (1-Bromo-3chloro-5.5-dimethylhdrantoin 95% other ingredients 4% - available bromine 63.5% available chlorine 28.2%) in a floater set to 6ppm. The bromine level was initially high when I added the granules (how high I don't know as the TF-100 only shows bromine levels up to 10ppm). However the bromine levels then dropped to ~ 1ppm with about 36 hours. Yesterday I topped the bromine up with the granules and it was at 6 ppm - today it is back to 1 ppm. Any idea why the bromine level keeps dropping in spite of the tablets in the floater. I used MPS--potassium monopersulfate to shock after adding the initial bromine.

PH is 7.2 TA is high at 320 (I am trying to get it down by adding a little acid each day to bring the PH down. My fill water is well water with high alkalinity.
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,083
San Rafael, CA USA
You may have gotten behind with bather load (mostly ammonia and urea in your sweat and urine) or you could have bacterial growth in the spa. These will consume a lot of bromine. Usually bromine from tablets is only sufficient to maintain bromine levels when you aren't using a spa, but when you use it you have to add oxidizer such as chlorine or MPS after every soak in sufficient quantity depending on the number of person-hours of soaking. Just keep adding an oxidizer until you measure a residual of bromine that mostly holds.
 

Vandergraff

Well-known member
Jun 22, 2010
84
chem geek said:
You may have gotten behind with bather load (mostly ammonia and urea in your sweat and urine) or you could have bacterial growth in the spa. These will consume a lot of bromine. Usually bromine from tablets is only sufficient to maintain bromine levels when you aren't using a spa, but when you use it you have to add oxidizer such as chlorine or MPS after every soak in sufficient quantity depending on the number of person-hours of soaking. Just keep adding an oxidizer until you measure a residual of bromine that mostly holds.
The spa was only filled 3 days ago - it is 'refurbished spa' which looked to in good clean condition when delivered from the spa shop. I'll try adding MPS to see what happens
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,083
San Rafael, CA USA
Oh, then that explains it. A new or refurbished spa was probably wet tested, but did not have the water in the pipes blown out. So bacteria can grow and form significant biofilm. You need to either superchlorinate or use a product like Spa System Flush or both. After this first time, you should be able to maintain your spa without the need for this procedure again, assuming you always maintain proper sanitizer levels.
 

Vandergraff

Well-known member
Jun 22, 2010
84
OK I may have overdone it the other way. The recommendation to superchlorinate and use Spa Flash came after we had drained it to level the spa a bit. So I thought I would try one more time with the bromine start up and if bromine use heavy then superchlorinate and/or use Spa Flash - I am using well water so I want limit number of drain fill cycles.

So I started up using the bromine instruction at the beginning of the thread but added 50% more bromine granules than recommended - now the bromine level is remaining very high and not dropping - how high is difficult to tell using the Block Test in the TF Kit it turns reddish(!) not yellow. Test strips read as 10ppm bromine max. It has been like this for couple of days - any way to bring the bromine level down? I added some non-chlorine shock.
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,083
San Rafael, CA USA
You normally superchlorinate starting with new fill water or water that doesn't have a bromide bank in it. So in your case, depending on how much sodium bromide you initially added after the fill, you have a lot of bromine, not just chlorine. If you want to lower it, you can neutralize it with a reducing agent. For pools, sodium thiosulfate is typically used, but for your spa you could use 3% hydrogen peroxide where 1 fluid ounce would neutralize roughly 3 ppm bromine in 350 gallons.

If you have the TF-100 test kit, then you can use the FAS-DPD chlorine test using a 5 ml water sample and each drop will be 2.25 ppm bromine. The orange in the OTO test would mean the bromine level is probably very high -- I'm guessing around 20-30 ppm or so (roughly 10-20 ppm chlorine equivalent).
 

Vandergraff

Well-known member
Jun 22, 2010
84
Sorry for second post in a new topic asking about the using the TF100 for bromine testing. You answered here. The bromine level is indeed very high - 15 drops with a 5ml sample so ~ 37.5 pmm. The OTO test is still orange. Using a test strip it says the bromine is only ~6pmm (the test strip claims to show levels up to 20 ppm and the purple is definitely close to the 6 pmm - not higher). I am going to read the thread below were someone else saw a big difference between the drop tests and test strips for bromine. Would you recommend using 3% hydrogen peroxide to bring down the bromine levels - or will they come down on their own over time. The water is clear without a strong smell of bromine - Ph and TA seem adjusted to be OK.
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,083
San Rafael, CA USA
Since it's bromine, which is not moderated in strength from CYA, I would bring the level down to around 10 ppm by using hydrogen peroxide. It should then be reasonable and will drop further from there on its own.
 

Vandergraff

Well-known member
Jun 22, 2010
84
OK I have added 6 fl oz of hydrogen peroxide - hopefully that will bring the bromine level down. Looking at the other thread about 'bromine mystery' will bromine be returned to the bromide 'bank'?
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,083
San Rafael, CA USA
For the most part, yes. When bromine gets used up it becomes bromide which can then be reactivated by adding more chlorine or MPS. There is some bromine lost from outgassing and some bromide/bromine lost from carry-out, but not too much. If you have an ozonator, then some bromine can be oxidized to bromate so would be lost that way.
 

Vandergraff

Well-known member
Jun 22, 2010
84
OK well that took the bromine level to 0-1 ppm (nothing registers on either the test strip TF100 FC test) the OTO test shows about 1ppm. What is the best way to get the bromine levels back up again. MPS or sodium bromide granules? 330 gallon hot tub no ozonator. I will put bromine tablets in a floater as well.
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,083
San Rafael, CA USA
You could just add some bleach or MPS, up to you (bleach is less expensive, of course). Each fluid ounce of 6% bleach in 350 gallons would increase the bromine level by around 3 ppm.

Since your bromine dropped more than expected, either your hydrogen peroxide was stronger (did it say 3% on the bottle?), your FAS-DPD testing had some problem, or my calculations were wrong. Anyway, it's easy to get the bromine back up a bit.

You shouldn't need to add any sodium bromide granules -- your bromide bank should be fine from the bromine you just neutralized back to bromide.
 

Vandergraff

Well-known member
Jun 22, 2010
84
Added some bleach (12.5% that I use for the pool at half the dosage) and that did it - Bromine back a reasonable level - hopefully it will stay there now. Thanks for your help.

(The hydrogen peroxide was 3% by the way and both the OTO / FAS-DPD testing were indicating very high bromine levels rior to adding it. The wild card was of course the test strips which consistently read much lower)
 

Ryl22

Member
Oct 4, 2010
5
I'm new on here and I just put in my pool this past summer. I struggled with the bromine level all summer and will take notes from these posts to hopefully fix this next season! Thanks!
 

Danmickread

Member
Jan 12, 2012
14
Hi,
I am a little unsure on the shocking stage after u have filled ur spa with fresh water.
You put the sodium bromide in and add an oxidiser to turn this into bromine but my question is how many ppm bromine reading should I be aiming for it does say u should get a reading of over 10ppm but more precisely how much over?
And say for example u say that the shocking level is 15ppm bromine what amount of chlorine (in ppm) do u add. What I am getting at is by looking on my bottle of dichlor to see how many grams to add to increase the chlorine level to say 10ppm for my amount of water how much would this raise the bromine level by?

Thanks

Dan
 
Status
Not open for further replies.