How to Maintain a Bromine Pool

[JPMorgan]

Can anyone give me the "skinny" on maintaining proper water chemistry with bromine? I am starting to help with an indoor condo pool that uses bromine and have never mainatined a bromine pool. What are the bromine levels I want to maintain? Do I do all the same tests that I would do on a chlorine pool with the exception of CYA.... and aim to maintain the same target levels as a chlorine pool? Can you do the FAS-DPD test with bromine? Do you shock regularly or not necessarily if proper bromine levels are consistently maintained? Any available overview that I can read on maintaining a bromine pool? Thanks.

 

[Donldson]

An indoor bromine pool isn't too much different than a chlorine pool with regards to pH, CH, and TA. If this is considered "public" (definitions vary by location) then you'll need to be sure to follow the guidelines by the local governing body. Total Bromine should generally be kept about 3-5 ppm and the SLAM level would be about 20 ppm.

Testing bromine with the FAS-DPD is only slightly different. You'll want to use a 25 ml sample and each drop will be 0.45 ppm (for normal operation levels rounding to 0.5 per drop will be easier and the difference will be negligible). You don't need to do the R-0003 step as the initial test is measuring Total Bromine and that's the number you work with.

Note that if you are using bromine tablets they contain a chemical that blunts bromine effectiveness in a somewhat similar manner as CYA. Over time it will build up and you might notice the bromine not keeping up like it did. This will be a sign that a partial drain and refill is in order. Unfortunately there isn't a test for this chemical at this time, you'll just have to keep an eye on how the pool reacts.

 

[JPMorgan]

I did first test of bromine today. Added sample water to 25ml line, then added the powder... using a speed stir. Then added drops of R-0871 until water sample cleared. Counted 26 drops before the sample cleared, so that's a reading of just under 13, correct (11.7 to be exact)? That's high based on parameters to maintain between 3-5. Is this a concern? I haven't been shown all the equipment yet, but I'm assuming there is a feeder in the equipment room that needs to be turned down. Should anyone be in the pool with bromine at that level or is it not an issue.

Found this in regs:
If bromine is used as a disinfectant, a bromine residual shall be maintained between 2.0 and 8.0 p.p.m. as total bromine. A bromine residual of at least 4.0 p.p.m. shall be maintained when the pool water temperature exceeds 85° F.

 

[Donldson]

Found this in regs:
If bromine is used as a disinfectant, a bromine residual shall be maintained between 2.0 and 8.0 p.p.m. as total bromine. A bromine residual of at least 4.0 p.p.m. shall be maintained when the pool water temperature exceeds 85° F.

You'll need to follow this then. Which means that 11.5 is too high to let people in. I don't know if you have to keep logs or have any kind of inspection, but not following it can open the condo up to trouble if someone's eyes start stinging and they decide it's because the rules weren't being followed. I've learned not to trust anyone when they feel they might be owed compensation for something.

See if you can find how the sanitizer is being introduced and shut it off until you get the level below 8 ppm. If it is being fed by tablets see if you can find out when a full or partial drain was last done. If it's been more than a year or two then it might be due for a partial one just to be sure the DMH (that's the CYA-like chemical found in bromine tablets) isn't too high.

 

[JPMorgan]

Have asked about bromine feeder and am waiting for info on how to reduce amount of bromine being introduced into the pool. Am attaching a pic of the bromine I find in the storage area. I'm assuming this is the stuff that adds the DMH. Is there another way to add bromine to a pool that causes less problems, i.e., a bromine powder, or other bromine product that doesn't add DMH? Testing Question: instead of filling vial to the 25 ml level and multiplying drops by .45 (or .5) couldn't I fill to 10 ml level and then multiply drops by 1.125? Would save on the R-0871. Basically I would be looking for the sample to turn clear after 4-5 drops... wouldn't that work?

 

[Donldson]

You can add any source of chlorine to activate the bromide in the water and create bromine. Liquid chlorine, trichlor, cal-hypo, etc. Just use the same 1 ppm FC = 2.25 ppm Br calculation.

Sure you could use a 10 ml sample and get 1-ish ppm precision. But do you use a 5 ml sample at home to get that precision? If you are aiming for a 4-8 ppm bromine level wouldn't a 2 ppm margin of error be difficult to handle? We're talking pennies per test, a few dollars a year.

 

[Mdragger88]

@Donldson
Not meaning to hijack - just have a little more understanding for myself & the op…
If trichlor or dichlor is used to activate the bromide will a build up of cya eventually affect the sanitizing process? If so, does this mean you should still monitor cya even though it is a bromine pool?

 

[Donldson]

@Donldson
Not meaning to hijack - just have a little more understanding for myself & the op…
If trichlor or dichlor is used to activate the bromide will a build up of cya eventually affect the sanitizing process? If so, does this mean you should still monitor cya even though it is a bromine pool?

CYA doesn't have a major effect on the ability of chlorine to activate bromide. It's kind of like how CYA doesn't affect the ability of the FAS-DPD test to measure FC, if that makes sense. This is why sodium bromide is sold as an algaecide, because if a pool has a major CYA problem then making it a bromine pool negates the CYA issue. Causes a million other issues, don't use that stuff in a chlorine pool, but that's another conversation. Eventually if the CYA level rose to several hundred ppm it might slow the ability of the chlorine to react with the bromide, but it would have to really be through the roof to cause any noticeable effect.

 

[JPMorgan]

If trichlor or dichlor is used to activate the bromide will a build up of cya eventually affect the sanitizing process? If so, does this mean you should still monitor cya even though it is a bromine pool?

Great question. Ask away. I'm trying to learn the maintenance "routine" for a bromine pool, so any questions help. Sounds like (to be ultra-conservative with respect to CYA, it might just make sense to stick with liquid chlorine to "activate the bromide in the water and create bromine", es[ecially in a smaller pool (20,000)
So, if bromine is the sanitizer and is being fed into the pool automatically, why do you add chlorine? Is that a weekly shock procedure or do you add chlorine when you get a low reading on bromine? It's a little confusing to me. Also assuming the bromine feeder has to be filled periodically with tablets, i.e., shut down pump, open feeder, and fill resrvoir. There should be a dial on that feeder to adjust the amount being fed into the pool, correct?

Also.... never got an answer to this question: Is there another way to add bromine to a pool that causes less problems, i.e., a bromine powder, or other bromine product that doesn't add DMH?

 

[JamesW]

Also.... never got an answer to this question: Is there another way to add bromine to a pool that causes less problems, i.e., a bromine powder, or other bromine product that doesn't add DMH?

Not really.

Maybe go to a SWG and it will be able to maintain the bromine from the chlorine generated.

 

[JoyfulNoise]

Those bromine tablets contain both chlorine and bromine. When they dissolve, the chlorine oxidizes any bromide in solution into sanitizing bromine. Adding an external source of chlorine (liquid chlorine for example) just does the same thing, chlorine converts bromide (spent bromine) back into active bromine. The pool water you are dealing with probably has hundreds of ppm’s worth of bromide ion in it. As soon as you add any chlorine, the chlorine turns into chloride and the bromide is converted into bromine. That’s the concept of a “bromide bank” - you have a ready supply of bromide in the water that you can convert to bromine.

 

[JPMorgan]

Maybe go to a SWG and it will be able to maintain the bromine from the chlorine generated.

Seems like SWGs are pretty rare around here for "public" pools. Both the currently contracted pool company and one other one I talked to don't manage any SWG pools and they made it sound like a conversion might be difficult (in terms of regulations in Illinois). I'll need to pursue it further to see what the issues are.

 

[JPMorgan]

Those bromine tablets contain both chlorine and bromine. When they dissolve, the chlorine oxidizes any bromide in solution into sanitizing bromine. Adding an external source of chlorine (liquid chlorine for example) just does the same thing, chlorine converts bromide (spent bromine) back into active bromine. The pool water you are dealing with probably has hundreds of ppm’s worth of bromide ion in it. As soon as you add any chlorine, the chlorine turns into chloride and the bromide is converted into bromine. That’s the concept of a “bromide bank” - you have a ready supply of bromide in the water that you can convert to bromine.

So.... I would add liquid chlorine to the pool water if I get a low bromine reading when testing? Is that correct? Let's say I get a reading of 2 and I want to get to 4.... would I enter 2 for FC in Pool Math to figure out how much bleach I need to add to the pool to get to 4.... or is the math different? Also, I have read that you shock a bromine pool weekly, but.... I also used to think that was necessary with a chlorine pool.... and I rarely shock my chlorine pool during the season now. Is it important with a bromine pool.... or will it be fine as long as I keep the levels within the right range and don't let it drop below the recommended minimum? The regs say to maintain between 2 and 8.

 

[JamesW]

they made it sound like a conversion might be difficult (in terms of regulations in Illinois).

Again, when someone begins to talk about regulations, ask them to show you the specific regulations they are referring to.

If they can't show you, then they should not be saying that the regulation exists, because they do not know what they are talking about and they are just making stuff up.

 

[JamesW]

The DMH is just like CYA for chlorine and it will quickly get out of control and it can make the water virtually impossible to control.

 

[JPMorgan]

Testing bromine with the FAS-DPD is only slightly different. You'll want to use a 25 ml sample and each drop will be 0.45 ppm (for normal operation levels rounding to 0.5 per drop will be easier and the difference will be negligible).

Is the powder for testing bromine different than the stuff you use for chlorine testing? I'm getting very different results when I do the FAS-DPD test than when I use the colormetric test (which is what the pool company uses). Here's what happening: I fill the test vial with water sample to the 25 ml line, set it on the SpeedStir, put one large scoop of the R-0870 powder in the vial, then start adding drops of R-0871 and divide the # of drops by 2 (multiply by .5). When testing recently, I counted 25 drops... about 12.5 ppm of bromine, right? Then, using the colormetric test, I filled the vial to the 9 ml mark, added 5 drops of R-001, then 5 drops of R-002, mixed the water in the vial and matched it to the closet color to get the reading. I get a reading of about 4 ppm! How can this be? Am I doing something wrong? Does the amount of R-0870 I put in make any difference? Should I try a test strip to see what kind of reading I get with that? Help!

 

[JoyfulNoise]

The R-0870 powder is the same for chlorine or bromine. The thing to understand about the FAS-DPD testing is that the indicator is sensitive to any oxidizer present, that's how it works. So in a chlorine pool, the DPD is reacting with chlorine to turn pink. In a bromine pool, the DPD is reacting with the bromine to turn pink. The FAS titrating drops are also not specific to chlorine or bromine, but the measured effect is different based on the fact that bromine has a different molecular weight than chlorine. That is why when you are testing for the sanitizer level the drops give 0.5ppm/drop for chlorine and 1.125ppm/drop for bromine (assuming a 10mL sample size). Aside from the difference in sensitivity, the chemistry of test is the same. The only other difference to note is that both bromine and it's combined form (bromamines) are strong enough oxidizers to both turn DPD pink, so the FAS-DPD test for bromine actually measures TOTAL bromine unlike the case with chlorine where the test can differentiate between free chlorine and combined chlorine.

Your titration test is the most accurate. Visual comparators are never very accurate and the chemicals can easily get bleached out by high bromine levels resulting in a false low reading. I would suggest when testing for bromine, you use a 10mL water sample AND you use two full scoops of R-0870 powder to ensure that you are seeing the true total bromine level.

 

[JPMorgan]

The only other difference to note is that both bromine and it's combined form (bromamines) are strong enough oxidizers to both turn DPD pink, so the FAS-DPD test for bromine actually measures TOTAL bromine unlike the case with chlorine where the test can differentiate between free chlorine and combined chlorine.

So..... when the regs say to maintain "free bromine" between 2ppm and 8ppm, isn't the titration test giving a high reading if it is atually measuring TOTAL bromine? If the tittration test measures TOTAL bromine, how do you measure free bromine with the titration test? I can envision knocking heads with the pool company because when they test, they are using the visual comparators. So I get a reading of 12.5 ppm (using titration) and they get 3-4 ppm (using visual comparator) and tell me they've never used the titration test and that they consistently get readings of about 3-4 ppm for our bromine pool. So one tester (pool company) records readings well within expected ranges, then I come along and tell them the reading I get is way over accpetable limits. That ain't gonna work! Do we insist they do the titration test (even though they are the "experts"). In actuallity, they are well within the regs which read as follows:
"If bromine is used as a disinfectant, a colorimetric test kit shall be provided that will determine free bromine residual and pH. The test kit shall include at least five bromine standards covering a range of 1.0 to 5.0 p.p.m." If I insist on the titration test (which I'm still not sure is the more accurate test for "free bromine", they can just say they are following the regs. I'm confused.

 

[JoyfulNoise]

You can’t measure “free” bromine with any colorimetric test whether it’s a comparator block or a titration test. The chemistry used is all the same. It’s TOTAL bromine, not free bromine. If the regulations are written that way then it’s basically a misunderstanding of bromine chemistry. And I sincerely doubt your pool “experts” are chemists. They took the CPO Course which is about as basic as the standard automobile driving course offered by a DMV. It gets you behind the wheel but doesn’t teach you a thing about what’s going on under the hood.

Your titration test is more accurate, and that is FACT. If the pool company that operates your pool wants to ignore that and use a cheap test then that is on them. You need to decide if you want all this headache associated with a community pool. Why are you assuming so much liability for no upside gain??

 

[JPMorgan]

Your titration test is more accurate, and that is FACT. If the pool company that operates your pool wants to ignore that and use a cheap test then that is on them. You need to decide if you want all this headache associated with a community pool. Why are you assuming so much liability for no upside gain??

Starting to question that myself.... especially if we are not on the same page about testing and maintenance. If the pool company and I were seeing eye to eye, then it might be a different story, but since you are telling me that the titration test is the more accurate test.... and we are getting readings that are quite far apart between the two tests.... then I may just bow out of this altogether unless they agree to use the titration test. I doubt they will.... takes a little more time.... and expect I will hear "we have always done it this way".

Question: So, if they are measuring bromine at 3-4 ppm using the color comparator test and I get 12-13 ppm with the titration test, is it even safe to go in the pool? The water looks good.... very clear.... but is it unsafe/ unhealthy if bromine is at 12? What are the potential harmful effects. Now I'm wondering if I even want to be in that pool.... or have my grandkids in there.