New to Bromine

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
11,760
Northern NJ


Bromine is very popular in hot tubs because there's lots of expensive chemicals the tub shops get to sell you. There's really not much advantage of bromine over chlorine and some people are actually allergic to bromine. If the tub has an ozone generator, then that can be used to regenerate spent bromide into bromine BUT the ozone systems fail pretty quickly and you literally have no way of knowing if it's working or not.

You can certainly try bromine out, there's a sticky on how to use bromine in the hot tub sub-forum, but a majority of TFP'ers prefer the dichlor-then-bleach method as it's easier to understand and you can use the test kit you have to get all the info you need.
 

CrystalSun

Silver Supporter
Jul 12, 2017
33
Brooklyn
Thanks for reply.
I have the feeling that chlorine is much simpler, you can figure out exactly how to dose by doing some calculations vs bromine + MPS where there's a lot of guesswork till you can figure it out. But what made us think of switching to bromine is that some claim that it's not as harsh as chlorine and it doesn't smell as bad. On the other hand I've seen people writing of terrible bromine smell and feel. So what's the TFP opinion?

Another question,
If doing bromide + bleach aren't we getting chloramines (CC) from the bleach that reacts with organic waste before working up with the bromide?
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
11,760
Northern NJ
Adding some CYA to the water buffers the harshness of chlorine. That is the purpose of using CYA in indoor pools or spas.
 

jmasone

Member
Jul 15, 2018
24
Stamford, CT
Thanks for reply.
I have the feeling that chlorine is much simpler, you can figure out exactly how to dose by doing some calculations vs bromine + MPS where there's a lot of guesswork till you can figure it out. But what made us think of switching to bromine is that some claim that it's not as harsh as chlorine and it doesn't smell as bad. On the other hand I've seen people writing of terrible bromine smell and feel. So what's the TFP opinion?

Another question,
If doing bromide + bleach aren't we getting chloramines (CC) from the bleach that reacts with organic waste before working up with the bromide?
I'm a bromine user and I happen to think it is super easy. My process is as follows:

1. On a new fill, to get things started, I add a packet of Sodium Bromide and oxidize with MPS (you can also use bleach or DiChlor to oxidize)
2. I put two bromine tablets in a floater, set it and forget it.
3. Once ever 1-2 weeks, I add another tablet to the floater.
4. If the tub is used heavily on a given day, I'll shock it with MPS (again, you can also use bleach or DiChlor to oxidize)

This method has worked flawlessly for me and has been relatively cheap. Unlike bleach, the bromine tablets have a fairly long shelf life and are not that expensive if you shop around. My sanitizer and pH levels have been very stable. Every now and then, I might need to add a little Sodium Bicarbonate (i.e. baking soda) to raise the pH and TA, but that's it. And, with bromine and MPS, I don't worry about CYA.
 

CrystalSun

Silver Supporter
Jul 12, 2017
33
Brooklyn
I'm a bromine user and I happen to think it is super easy. My process is as follows:

1. On a new fill, to get things started, I add a packet of Sodium Bromide and oxidize with MPS (you can also use bleach or DiChlor to oxidize)
2. I put two bromine tablets in a floater, set it and forget it.
3. Once ever 1-2 weeks, I add another tablet to the floater.
4. If the tub is used heavily on a given day, I'll shock it with MPS (again, you can also use bleach or DiChlor to oxidize)

This method has worked flawlessly for me and has been relatively cheap. Unlike bleach, the bromine tablets have a fairly long shelf life and are not that expensive if you shop around. My sanitizer and pH levels have been very stable. Every now and then, I might need to add a little Sodium Bicarbonate (i.e. baking soda) to raise the pH and TA, but that's it. And, with bromine and MPS, I don't worry about CYA.
Thanks for clear response!
How do you figure out dosage of MPS?
I'm afraid of getting bromine too high as my spa -Mikvah- is used every day but on the other hand don't wanna go low...
 

dlleno

Well-known member
Sep 9, 2016
90
denver, CO
I too just don't get why bromine is considered difficult, but its true that the retail market has contributed to this misconception. Some prefer the odor over chlorine; some find allergies to one vs the other, so its a personal choice. Here are some bromine myths

1. bromine is incompatible with "dichlor then switch to bleach". I'm following exactly the same procedure with bromine as I do with chlorine, except that on start-up I add bromide salts. I set aside the amount of dichlor that represents the target CYA and i just use that as the oxidizer to accomplish the conversion to bromine. when the dichlor is used up I switch to bleach as the oxidizer that converts bromide salts to bromine. There are some really cool and fancy names for this method but I just call it "dichlor switch to bleach" because thats what it is. one could argue that CYA isn't needed in a bromine spa at all, which suggests that one could use bleach as the oxidizer from startup, but to be safe I wouldn't do it. I'm just not a chemist so I can't prove it.

2. MPS is preferred or otherwise associated with bromine. One can certainly use MPS in a bromine spa (I have) but its "non chlorine" attractiveness is actually more prominent in a chlorine spa because in a chlorine spa it oxidizes contaminants as MPS. In a bromine spa it's primary action is to convert bromide salts to bromine. There is a small benefit before the conversion to bromine is complete, but beyond that, the use of MPS isn't that much different from chlorine as the oxidizer -- the end result is still bromine

3. Bromine is more difficult than chlorine. I just don't get this. add bromide salts at startup, and everything else is the same. no floater, no magic . exactly the same as "dichlor then switch to bleach"

the non-myth advantage of bromine is that with ozone in place the sanitizer decay rate is measurably better/lower and asymptotically approaches zero as time passes! that means under ideal conditions bromine never goes to zero. this means, unless you have biofilms eating your sanitizer, you can leave for days. I have personally done this, and measured .5 to 1ppm bromine after several days, although I will emphasize that this does take a very clean/purged spa and most spas won't perform this way unless regularly purged with ahhsome.

The only disadvantage of bromine I have found is that when you have ozone and clean spa and you shock, it can take days before the bromine level calms back down so you can get in! ... and Hydrogen peroxide can't be used to neutralize it!

Ozone generators do wear out, but if you are using ozone for its ozone effectiveness -- you'll get more mileage out of a bromine spa. ozone and bromine is a beautiful thing and when the ozone generator wears out -- replace it! in fact, the bromine decay rate can be used to measure ozone effectiveness!

some things that make bromine difficult

1. floaters. to each his own but i just don't see the advantage. never had a bromine floater
2. "brominating concentrate" this is just a mixture of dichlor and sodium bromide. you can use it in a pinch, but at startup you won't have a bromine spa you will have a partial bromine spa. I'd rather put the sodium bromide in myself and choose dichlor for the oxidizer
 
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CrystalSun

Silver Supporter
Jul 12, 2017
33
Brooklyn
I too just don't get why bromine is considered difficult, but its true that the retail market has contributed to this misconception. Some prefer the odor over chlorine; some find allergies to one vs the other, so its a personal choice. Here are some bromine myths

1. bromine is incompatible with "dichlor then switch to bleach". I'm following exactly the same procedure with bromine as I do with chlorine, except that on start-up I add bromide salts. I set aside the amount of dichlor that represents the target CYA and i just use that as the oxidizer to accomplish the conversion to bromine. when the dichlor is used up I switch to bleach as the oxidizer that converts bromide salts to bromine. There are some really cool and fancy names for this method but I just call it "dichlor switch to bleach" because thats what it is. one could argue that CYA isn't needed in a bromine spa at all, which suggests that one could use bleach as the oxidizer from startup, but to be safe I wouldn't do it. I'm just not a chemist so I can't prove it.

2. MPS is preferred or otherwise associated with bromine. One can certainly use MPS in a bromine spa (I have) but its "non chlorine" attractiveness is actually more prominent in a chlorine spa because in a chlorine spa it oxidizes contaminants as MPS. In a bromine spa it's primary action is to convert bromide salts to bromine. There is a small benefit before the conversion to bromine is complete, but beyond that, the use of MPS isn't that much different from chlorine as the oxidizer -- the end result is still bromine

3. Bromine is more difficult than chlorine. I just don't get this. add bromide salts at startup, and everything else is the same. no floater, no magic . exactly the same as "dichlor then switch to bleach"

the non-myth advantage of bromine is that with ozone in place the sanitizer decay rate is measurably better/lower and asymptotically approaches zero as time passes! that means under ideal conditions bromine never goes to zero. this means, unless you have biofilms eating your sanitizer, you can leave for days. I have personally done this, and measured .5 to 1ppm bromine after several days, although I will emphasize that this does take a very clean/purged spa and most spas won't perform this way unless regularly purged with ahhsome.

The only disadvantage of bromine I have found is that when you have ozone and clean spa and you shock, it can take days before the bromine level calms back down so you can get in! ... and Hydrogen peroxide can't be used to neutralize it!

Ozone generators do wear out, but if you are using ozone for its ozone effectiveness -- you'll get more mileage out of a bromine spa. ozone and bromine is a beautiful thing and when the ozone generator wears out -- replace it! in fact, the bromine decay rate can be used to measure ozone effectiveness!

some things that make bromine difficult

1. floaters. to each his own but i just don't see the advantage. never had a bromine floater
2. "brominating concentrate" this is just a mixture of dichlor and sodium bromide. you can use it in a pinch, but at startup you won't have a bromine spa you will have a partial bromine spa. I'd rather put the sodium bromide in myself and choose dichlor for the oxidizer
Thanks for your time dlleno. The reason I find it difficult -guesswork- is because due to my question below I think that MPS would be what I wanna use to oxidize and I haven't seen an exact formula to figure out how to dose MPS
Another question,
If doing bromide + bleach aren't we getting chloramines (CC) from the bleach that reacts with organic waste before working up with the bromide?
 

dlleno

Well-known member
Sep 9, 2016
90
denver, CO
Thanks for your time dlleno. The reason I find it difficult -guesswork- is because due to my question below I think that MPS would be what I wanna use to oxidize and I haven't seen an exact formula to figure out how to dose MPS
I hear you, and although I can't answer your question precisely (chem geek is a physical chemist if memory serves. he could probably write the formula and calculate the right answer), I would offer that a simple experiment would yield the results you want. typically MPS is used, recommended and formulated for its shock properties in a chlorine spa because its oxidizing behavior works differently than chlorine and does not disturb the chlorine level itself. So very few have used it as the primary oxidizer in a bromine spa. start with a tablespoon and then wait an hour and measure the bromine level. then try more or less MPS until you dial it in. you could quickly take the guess work out of it by simply recording the bromine level you get with a given volume of MPS. If you get twice as much bromine as you want, then cut the MPS in half next time, etc.

something else to consider is to re-think the goal of using MPS as the primary oxidizer for a bromine spa. dichlor is effective and efficient (and probably less expensive) and does not introduce chlorine -- it produces bromine. In my spa I don't use MPS as a "sanitizer" (which is the net effect in a bromine spa) I use it as an occasional shock. I would offer that dichlor is a better choice for the primary/daily sanitizer dose (which will produce bromine).

re chloramines and the accumulation of combined chlorine -- I'm going to defer to the chemists among us for the engineering answer, but my observational suggestion is that the CC issue is only relevant to the extent that chlorine is used to oxidize bather waste -- which is the primary CC mechanism in a chlorine spa. But for a bromine spa, chlorine doesn't oxidize bather waste (except for a small amount before the conversion is complete) -- it converts bromide salts to bromine -- this i think explains the best practice to use chlorine as the daily "sanitizer" (to produce bromine) and then shock with MPS every 1-2 weeks.
 
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CrystalSun

Silver Supporter
Jul 12, 2017
33
Brooklyn
I hear you, and although I can't answer your question precisely (chem geek is a physical chemist if memory serves. he could probably write the formula and calculate the right answer), I would offer that a simple experiment would yield the results you want. typically MPS is used, recommended and formulated for its shock properties in a chlorine spa because its oxidizing behavior works differently than chlorine and does not disturb the chlorine level itself. So very few have used it as the primary oxidizer in a bromine spa. start with a tablespoon and then wait an hour and measure the bromine level. then try more or less MPS until you dial it in. you could quickly take the guess work out of it by simply recording the bromine level you get with a given volume of MPS. If you get twice as much bromine as you want, then cut the MPS in half next time, etc.

something else to consider is to re-think the goal of using MPS as the primary oxidizer for a bromine spa. dichlor is effective and efficient (and probably less expensive) and does not introduce chlorine -- it produces bromine. In my spa I don't use MPS as a "sanitizer" (which is the net effect in a bromine spa) I use it as an occasional shock. I would offer that dichlor is a better choice for the primary/daily sanitizer dose (which will produce bromine).

re chloramines and the accumulation of combined chlorine -- I'm going to defer to the chemists among us for the engineering answer, but my observational suggestion is that the CC issue is only relevant to the extent that chlorine is used to oxidize bather waste -- which is the primary CC mechanism in a chlorine spa. But for a bromine spa, chlorine doesn't oxidize bather waste (except for a small amount before the conversion is complete) -- it converts bromide salts to bromine -- this i think explains the best practice to use chlorine as the daily "sanitizer" (to produce bromine) and then shock with MPS every 1-2 weeks.
Please CMIIW but with chorine/bromine it’s not so accurate to figure out dosage by measuring how much sanitizer is in the water after introducing it into the water as you can’t know how how much was depleted by organic waste etc.

Re CC. In a Mikvah/spa that’s being used by approx 30 people in a 6 hour period I believe there’s plenty of organic matter to create CC before it’s turning into bromine.

Wrong?
 

Sjde

Well-known member
Apr 29, 2016
243
Denver CO
We've been using bromine in a 375 gallon spa for 3 years. I find if the bromine tests 0-1 after use, I can use 1 tbls MPS to get it to about 4 ppm. Or I can use 1/2 -1 tsp dichlor. You just need to check before and after. We do use a floater since it's in a vacation rental and can be used for days without being checked.
 

wogster

In The Industry
Apr 30, 2018
112
Toronto, Ontario, Canada
Bromine is supposed to tolerate the heat better then chlorine, since bromine turns to bromide and you need an oxidiser to turn it back into bromine, you can measure the level, add some chlorine, and then measure the level again, keep notes as to how much chlorine you need to raise your bromine level a certain amount, and your golden. For the Mikvah, is this in a public place, if so, check your state and local laws, it may be classed as a public pool, and then what you do, and how you do it, may be dictated by the state. Yes TFP may be a wonderful way of doing things, but government rules regarding pools, have not really changed since the 1970's; and mesh nicely with getting pool stored....
 

dlleno

Well-known member
Sep 9, 2016
90
denver, CO
Please CMIIW but with chorine/bromine it’s not so accurate to figure out dosage by measuring how much sanitizer is in the water after introducing it into the water as you can’t know how how much was depleted by organic waste etc.
I never perform experiments under load, prefering some down time when the water is stable . There's always a gap between theory and practice and one just has to play the cards that you've been dealt. Even if pool math (for example) could calculate the bromine production per quantity of mps the numbers would be similarly inaccurate under heavy loads as well, and only experience will bridge the gap

Re CC. In a Mikvah/spa that’s being used by approx 30 people in a 6 hour period I believe there’s plenty of organic matter to create CC before it’s turning into bromine.

Wrong?
The only way to know the answer is to understand the the conversion process itself at the chemical level and how long it takes. What we do know is that the CCs produced during the bromine conversion is severely constrained by time compared to a chlorine spa. Its a small problem

Note that cc's can be controlled in a properly maintained chlorine spa and the task is even more easily accomplished in a bromine spa. Im just not familiar with the TDS or other long term side effects of using mps as the primary or only oxidant and id have to see some experimental results or other studies to comment beyond the current best practices