In A Chemical Stew

[chemtexx]

Allrighty then.... I took delivery on a Jacuzzi brand J335, 450 gallon (give or take) spa in late June. It came with a chemical kit and lucky me... I've got a pool n spa store just down the street. Well I used the kit, fairly basic. Bromine biscuits, bicarb, smellum good, the usual.... Ok for 3 months or so, all was reasonably good but I did buy defoamer, water clarifier, some enzyme stuff, sulfamic acid, and monkey spit from the local spa store in order to keep the water handsome and comfy. Well last weekend, it had the unmistakeable smell of lake water. Something's gotta go.... So Tuesday evening I drained the swamp. Wednesday evening I refilled the swamp. It's Saturday morning and it's worse than a swamp. It's hazy, foamy, and smells worse than a freaking lake.

Since the refill... two monopersulfate shocks, a pH down adjustment, reload of bromine biscuits, a feed of bromide starter, a shot of stabilized sodium bromine... i think that's it. Like sitting in a sewer this morning. I'm assuming the odor is due to bacterial action. I had a spa for 3 years in the 90's never once had this trouble... is it the bromine vs. chlorine?

Oh and the joker at the pool store said 1) hardness is calcium, magnesium has nothing to do with it and 2) spas don't ever get hard water.... Having a chemistry degree and having worked with industrial steam a good part of my life I've dismissed him as an idiot and moved on. But still I have a stinky sinky. Obviously I'm overtreating but what would you recommend?

[gman]

The following is copied from a post by Waterbear in response to a question about the step-by-step Bromide system. It was taken from the Hot Tub Water Chemistry topic under the Pool/Spa Water Care section of this forum. I posted it for you since you are using a bromide system. Since you also asked about the difference in bromide v. chlorine, I've also posted a link to Nitro Dichlor/Bleach method, which many tub owners subscribe to, including me. Nitro's Approach to Water Maintenance. You may find this information helpful. Good luck.

From Waterbear

Bromine is easy if done right! Most people do not understand the chemistry and do it wrong, including many dealers!

When testing water do NOT use strips, get a good drop based test kit. Your best bet for Bromine is the Taylor k-2106 and for chlorine the K-2006 (NOT the K-2005). THE TEST KIT IS PROBABLY THE MOST IMPORTANT THING YOU CAN OWN FOR EASY SPA MAINTENANCE. GET A GOOD ONE! I cannot stress this enough!!!!!

On to bromine:

1. fill the spa and balance the water. If you have well water or know your water has metals then add a metal sequestrant at this point. You will need to continue with weekly maintenace doses of the metal sequestrant if your water has metals. A better solution is to fill from a water softener or purchase a "spa stick" filter that attaches to your hose to fill the spa to help remove the metals.

A,adjust TA to about 100 ppm (search the forum for how to lower TA by using acid and aeration, raise TA with baking soda, it;s the same chemical sold as TA increaser for much less money!

B. Once TA is adjusted then adjust pH to between 7.4 and 7.8 Use dry acid to lower pH if too high, Use borax from the laundry aisle to raise it if too low.Do NOT use pH up because it will make your TA go too high!!!!!!!! pH up is sodium carbonate, also known as washing soda and raises both pH AND TA!

C. IF you calcium hardness is below 130 ppm raise it to 130-150. If it is above 400 then add an anti stain and scale or calcium reducer to the spa weekly. If it is between 130-400 you are fine.

2. Add 1/2 oz of sodium bromide per 100 gallons of water to create your bromide reserve in the water. This is the MOST important step with a bromine spa and the one most people ignore. If you omit this step you will not have a bromine spa for several weeks until enough tablets dissolve in the water to create the bromide bank and you will not have sanitized water! Sodium Bromide is available in packets and jars from several companies. You will need to re add it on each drain and fill.

3. Shock the spa to 'activate' (oxidize) the sodium bromide into hypobromous acid (this is your 'bromine' sanitizer that you test for with your strips or test kit.) You can use MPS to shock but chlorine works just as well if not better and is much less expensive. One of the best sources of chlorine you can use with a bromine spa is sodium hypochlorite and that can also be found in the laundry aisle. It is ordinary liquid chlorine bleach. You want the regular, unscented bleach, not a thickened or scented one. It will come in either 5.25% or 6%. Read the label to see which you have. Use 2.5 oz (5 tablespoons) of the 5.25% or 2 oz (4 tablespoons) of the 6% per 100 gallons of spa water to shock. Your bromine will go very high. Uncover the spa and circulate until the bromine drops below 10 ppm before you use the spa.

4. Put in the floater with your bromine tabs (which usually contain BOTH bromine and chlorine to activate the bromine, btw) and adjust the floater to maintain your bromine at about 4-6 ppm. this can take a bit of trial and error. Check your pH and bromine before you go ineach time and if bromine is low add a few tablespoons of bleach and retest until it is above 4 but below 10 ppm. It really only takes seconds for the chlorine to oxidize your bromide reserve into bromine sanitizer. If pH is not between 7.2 and 8.0 then you should adjust it before entering the spa and wait abot 30 minutes then retest it to make sure it is in the proper range. If both are off then adjust pH first then the bromine. If your bromine is always low open the floater a bit more. If high then close it down a bit. If it is above 10 then take out the floater and open the spa until the bromine level drops below 10 before entering the water and close the floater down a bit. Once you get the floater adjusted the bromne level will stay pretty constant and it becomes much easier! Remember to keep tablets in the floater at all times!

You are done!

Weekly test pH, Keep pH between 7.2 -8.0 and then when you have finished adjusting shock the spa with bleach just like when you added the sodium bromide but you do not need more sodium bromide. Add anti scale or calcium reducer if your calcium tested above 400 ppm.

Monthly check and adjust TA and calcium before you adjust pH and shock.

Every 3-4 months drain, refill, balance the water, add the sodium bromide, shock, and put the bromine tablets back in.

Actually pretty easy!

If you follow these steps you will not need to waste money on defoamers, clarifier, enzymes, etc.!

Hope this helps.

Chlorne is a bit cheaper than bromine but it really does require daily attention. Bromine (and what I described above is known as 3 step bromine and is the most forgiving) is not as fussy (acceptable pH range is wider and water balance is easier than chlorine or 2 step bromine) and really only needs attention once or twice a week after you get it set up, besides checking sanitizer level and pH before you enter the spa each time.

gman

[NewB@Spa]

gman was spot on with most of his points/advice. I did not notice one critical piece of advice. DECONTAMINATE your tub immediately. I did not catch whether this was a new or used tub, but in light of the bacteria issues you are having it is highly recommended. Use Nitro's Decon procedure; Decontamination. I had an issue with water that I could not get in balance and was causing folliculitis. I decontaminated using Spa System Flush-System Flush. Then I would refill and balance according to whatever method you are using.

[waterbear]

Oh and the joker at the pool store said 1) hardness is calcium, magnesium has nothing to do with it and 2) spas don't ever get hard water

He is partly correct in his ignorance. Magnesium hardness (and therefore total hardness) is not an issue. In plaster and fiberglass spas only calcium hardness is of interest. (This is another reason test strips are not very useful. They only measure total hardness and not calcium hardness.) In a plaster spa too little calcium will cause it to leach from the plaster thereby damaging it. In a fiberglass shell it can lead to cobalt leaching from the gelcoat and a higher tendency for metal staining. Also, calcium is reactive with the bicarbonate buffer system we call total alkalinity and too high a level combined with a pH spike can cause calcium to precipitate out of the water as scale deposits no matter what the surface of the tub.

Hope this clarifies it for you.

[quantumchromodynamics]

I think that your problem might be associated with high levels of DMH (DimethylHydantoin). DMH is the carrier chemical for bromine tabs and is similar to cyanuric acid. It combines with bromine and helps protect it from degradation by sunlight and ozone. It also slows down the reaction rate of bromine in a similar way to how cyanuric acid slows down the reaction rate of chlorine. The only problem is that we do not know how much of an effect the DMH has on the bromine.

I recommend that DMH be limited to 100 ppm. Some references show a 200 mg/l (ppm) limit.

DMH below a maximum of 200 mg/L.

http://www.health.vic.gov.au/phwa/downloads/submissions/moorabool_shire_council.pdf

Like the chlorinated isocyanurates, failure to maintain the correct relationship between the disinfectant residual and the organic component can result in unsatisfactory microbial conditions. The level of dimethylhydantoin in the water must be limited and should not exceed 200 mg/l. http://www.who.int/water_sanitation_health/bathing/srwe2chap5.pdf

Where bromochlorodimethylhydantoin is used, the maximum dimethylhydantoin concentration shall be 200 mg/L.

Reference

Since there is no regular test kit available for DMH, you will need to determine the level by determining the total amount of DBDMH (1,3-dibromo-5,5-dimethylhydantoin) or BCDMH (1-bromo-3-chloro-5,5-dimethylhydantoin), also called organic bromine.

For every 10 ppm of bromine supplied by DBDMH, you will get 4 ppm of DMH.

Every 1 ounce of DBDMH added to 100 gallons of water will add 83.72 ppm of bromine and 33.56 ppm of DMH.

Assuming a 0.70-ounce tab, every DBDMH bromine tab will add 58.60 ppm of bromine and 23.49 ppm of DMH to 100 gallons of water.

1 DBDMH bromine tab added to 400 gallons of water will add 14.65 ppm bromine (measured as Br₂) and will add 5.87 ppm of DMH.

Every 1 ounce of BCDMH added to 100 gallons of water will add 99.13 ppm of bromine and 39.74 ppm of DMH. (I counted the chlorine as bromine since it will oxidize bromide to bromine quickly.)

A 400 gallon tub should limit the total use of bromine tabs to 10 ounces (weight) of BCDMH ((14) 0.70-ounce tabs) or 12 ounces of DBDMH. I recommend that the use of bromine tabs be minimized as much as possible to reduce the effect of the DMH since we do not know how much the effect is.

You should use regular, unscented 6 % bleach to provide as much of the sanitizer as possible.

You should definitely do the Decontamination procedure.

What test kit do you have?

How much weight of bromine tabs have you used since the original fill?

What do you keep your bromine level at?

Note: there is also a newer formulation of bromine BCDMH + DCDMH + DCEMH (1-bromo-3-chloro-5,5-dimethylhydantoin + 1,3-dichloro-5,5-dimethylhydantoin + 1,3-dichloro-5-ethyl-5-methylhydantoin), sometimes referred to as Dantobrom.

[waterbear]

I think that your problem might be associated with high levels of DMH (DimethylHydantoin). DMH is the carrier chemical for bromine tabs and is similar to cyanuric acid. It combines with bromine and helps protect it from degradation by sunlight and ozone. It also slows down the reaction rate of bromine in a similar way to how cyanuric acid slows down the reaction rate of chlorine. The only problem is that we do not know how much of an effect the DMH has on the bromine.

I recommend that DMH be limited to 100 ppm.

Since there is no regular test kit available for DMH, you will need to determine the level by determining the total amount of DBDMH (1,3-dibromo-5,5-dimethylhydantoin) or BCDMH (1-bromo-3-chloro-5,5-dimethylhydantoin), also called organic bromine.

For every 10 ppm of bromine supplied by DBDMH, you will get 4 ppm of DMH.

Every 1 ounce of DBDMH added to 100 gallons of water will add 83.72 ppm of bromine and 33.56 ppm of DMH.

Assuming a 0.70-ounce tab, every DBDMH bromine tab will add 58.60 ppm of bromine and 23.49 ppm of DMH to 100 gallons of water.

1 DBDMH bromine tab added to 400 gallons of water will add 14.65 ppm bromine (measured as Br₂) and will add 5.87 ppm of DMH.

Every 1 ounce of BCDMH added to 100 gallons of water will add 99.13 ppm of bromine and 39.74 ppm of DMH. (I counted the chlorine as bromine since it will oxidize bromide to bromine quickly.)

A 400 gallon tub should limit the total use of bromine tabs to 10 ounces (weight) of BCDMH ((14) 0.70-ounce tabs) or 12 ounces of DBDMH. I recommend that the use of bromine tabs be minimized as much as possible to reduce the effect of the DMH since we do not know how much the effect is.

You should use regular, unscented 6 % bleach to provide as much of the sanitizer as possible.

You should definitely do the Decontamination procedure.

What test kit do you have?

How much weight of bromine tabs have you used since the original fill?

What do you keep your bromine level at?

Note: there is also a newer formulation of bromine BCDMH + DCDMH + DCEMH (1-bromo-3-chloro-5,5-dimethylhydantoin + 1,3-dichloro-5,5-dimethylhydantoin + 1,3-dichloro-5-ethyl-5-methylhydantoin), sometimes referred to as Dantobrom.

Wow,

Enough to make me give up a hot tub for good. Bottom line, real world experience shows that if create your bromide bank on each fill with sodium bromide, shock once a week with your oxidizer of choice (I prefer sodium hypochlorite), tabs to maintain a working bromine level in the water, and change the water every 3 or 4 months then bromine is really easy to do. I prefer my advanced chemistry in the lab and not in the tub (and I do have experience with that also.)

[quantumchromodynamics]

Waterbear, I know that you worked in retail, and that you have a lot of experience working one-on-one with customers. When you're working one-on-one, you can assess the person's level of experience and tailor the advice to what they are comfortable with. The poster does note that they are familiar with chemistry and have a degree, so I don't think that they will be too overwhelmed.

I think that the internet is a unique opportunity to go beyond simple answers and try to give people more detail, and explain the reasons behind the advice.

The original poster is not the only person who reads the advice. There are tens or hundreds of people who will read the advice. Each person is at a different experience and skill level. Many of them want to know more than just simple answers. There are many service people who read the advice who can learn something new and improve their ability to give good service.

You have certainly written many posts that contain technical details that have educated many service people. Many customers are getting much better service from professionals who have read your posts and applied the knowledge.

I try to give more detail for those who are interested, and I also try to make sure that the advice is usable by those who don't want to know the details.

Many customers are given easy answers. The problem is that the answers are often wrong. In fact, most people who come on the boards are doing so because they have lost faith in some pool person or company who has been giving them easy answers and they are getting poor results. I would expect them to be a little leery and skeptical about simple advice. If some parts of the advice are too technical for someone, then they can just skip over it. Everyone doesn't have to understand everything all of the time.

You know as well as I do that there are a lot of myths and misinformation within the industry. If service is going to improve, then we are going to have to get into the details and the science.

[quantumchromodynamics]

To calculate the hardness of your water, you can use the pool calculator. It calculates the CSI (Calcite Saturation Index). Be sure to fill in all of the boxes including temperature to get an accurate CSI calculation.

A CSI of 0.0 means that the water is fully saturated with calcium carbonate. If you have plaster or grout, then you want a CSI of 0.0 to +0.1. If you don't have plaster or grout, then you want a CSI of -0.3 to -0.1 to avoid scaling.

The pool calculator accounts for borate and cyanurate alkalinity, but not phosphate or dimethylhydantoin alkalinity. Phosphate alkalinity can be ignored unless you have added a phosphate based pH buffer. Dimethylhydantoin alkalinity is negligible unless the pH is high and the level of dimethylhydantoin is very high. Dimethylhydantoin has a pKa of 9.19. Here are the correction factors for DMH:

pH........% DMH

7.0..........0.251

7.1..........0.315

7.2..........0.396

7.3..........0.497

7.4..........0.623

7.5..........0.78

7.6..........0.98

7.7..........1.22

7.8..........1.53

7.9..........1.91

8.0..........2.37

For example, at a pH of 7.9 and a DMH level of 200 ppm, the DMH will contribute 3.82 ppm to the TA.

You should clean your filters according to the instructions here. Most TSP that you will find locally is not real TSP, and does not work as well as real TSP. You can get real TSP here. You should get a second set of filters so that you can allow one to soak while using the other set.

I also recommend that you add 50 ppm borates using boric acid, which you can get here.

[waterbear]

Waterbear, I know that you worked in retail, and that you have a lot of experience working one-on-one with customers. When you're working one-on-one, you can assess the person's level of experience and tailor the advice to what they are comfortable with. The poster does note that they are familiar with chemistry and have a degree, so I don't think that they will be too overwhelmed.

I think that the internet is a unique opportunity to go beyond simple answers and try to give people more detail, and explain the reasons behind the advice.

The original poster is not the only person who reads the advice. There are tens or hundreds of people who will read the advice. Each person is at a different experience and skill level. Many of them want to know more than just simple answers. There are many service people who read the advice who can learn something new and improve their ability to give good service.

You have certainly written many posts that contain technical details that have educated many service people. Many customers are getting much better service from professionals who have read your posts and applied the knowledge.

I try to give more detail for those who are interested, and I also try to make sure that the advice is usable by those who don't want to know the details.

Many customers are given easy answers. The problem is that the answers are often wrong. In fact, most people who come on the boards are doing so because they have lost faith in some pool person or company who has been giving them easy answers and they are getting poor results. I would expect them to be a little leery and skeptical about simple advice. If some parts of the advice are too technical for someone, then they can just skip over it. Everyone doesn't have to understand everything all of the time.

You know as well as I do that there are a lot of myths and misinformation within the industry. If service is going to improve, then we are going to have to get into the details and the science.

You leave out that I also have a background in chemistry. I still stand by what I said. While it is known that dimethylhydantion does make bromine "permanent" and not destroyed by sunlight there is no empirical evidence that, under normal usage such as I outline in the post quoted by gman will cause 'overstabiliizaton' as an excess of cyanuric acid does in a chlorine system. If you have evidence to the contrary I would be most interested in seeing it so please post the links. Thanks!

P.S. I do appreciate the way you constantly reiterate my warnings about TSP substitutes vs. TSP (and the fact that real TSP is not readily available in many areas in efforts to limit phosphate pollution in groundwaters (something I know a bit about, having been involved in research in oceanographic P. Chem in the 70's on the effects of various ions, including phosphates, on the precipitation and nucleation of calcium carbonate from seawater and seawaterlike solutions), having a second set of cart filters so they can be rotated while one set is soaking, and adding borates to 50 ppm! I wonder where you first read about these things?

Oh, you forgot to mention that bromamines have been reported to have a 'fishy' smell that is often corrected by shocking (oxidizing to raise bromine levels above 10 ppm) and allowing the spa to remain uncovered until bromine levels drop to normal range.

You are preaching to the choir when you state that

there are a lot of myths and misinformation within the industry

However, unless additional info is requested, which is best done by providing links or starting a new thread and linking to it, IMHO, it is best to keep answers as general as possible to keep them accessible to the widest audience (the educator in me is coming out here, another had I have worn and currently wear, btw) so you do not lose a large percentage of the readers without the strong chemistry background to even begin to comprehend what you posted above.

There is absolutely nothing wrong with the info you posted. However, there is a time and place for theoretical chemistry and a time and place for practical answers. In this case we have a new spa owner with a chemistry background and not a good understanding of spa water chemistry (as evidenced by his confusion over total hardness and calcium hardness when it comes to water balance) that does not seem to have a plan on how to properly use bromine, as avidenced by

Since the refill... two monopersulfate shocks, a pH down adjustment, reload of bromine biscuits, a feed of bromide starter, a shot of stabilized sodium bromine... i think that's it.

stabilized sodium bromine? a new one on me and an indicator of a new spa owner who does not understand the chemistry of he is using in his spa. MPS is not going to do much of anything until the sodium bromide is added so I hope this is not the order these things were done. I assume the 'feed of bromide starter' is sodium bromide added at .5 oz per 100 gallons of water. After the addition of this THEN shocking with MPS (or chlorine) is the proper procedure.

Obviously I'm overtreating but what would you recommend?

and here the OP is asking for help and gman provided that. Let him get the spa running properly and I am confident that his problems will disappear.

[quantumchromodynamics]

You leave out that I also have a background in chemistry.

The poster notes that they have a background in chemistry and a chemistry degree. Therefore, I think that they would have an interest in the chemistry involved.

While it is known that dimethylhydantion does make bromine "permanent" and not destroyed by sunlight there is no empirical evidence that, under normal usage such as I outline in the post quoted by gman will cause 'overstabiliizaton' as an excess of cyanuric acid does in a chlorine system. If you have evidence to the contrary I would be most interested in seeing it so please post the links. Thanks!

DMH below a maximum of 200 mg/L.

http://www.health.vic.gov.au/phwa/downloads/submissions/moorabool_shire_council.pdf

The level of dimethylhydantoin in the water must be limited and should not exceed 200 mg/l. There is no poolside test kit available, and the need to regularly monitor dimethylhydantoin by a qualified laboratory is a disadvantage of the use of BCDMH.

http://www.who.int/water_sanitation_health/bathing/srwe2chap5.pdf

Where bromochlorodimethylhydantoin is used, the maximum dimethylhydantoin concentration shall be 200 mg/L.

Reference

Here is what I said:

The only problem is that we do not know how much of an effect the DMH has on the bromine.

My opinion is that until we know for sure the accurate equilibrium equations, we should try to minimize the amount of DMH. It is safer to minimize than not. The above references indicate 200 ppm as the recommended upper limit. I assume that they have reasons and evidence to support their advice. I think that a hot tub that relies heavily on bromine tabs and has high usage could exceed 200 ppm in a 4 month period. Further, if the DMH does have even a fraction of the effect of cyanuric acid, then unless one maintains a proper ratio, the tub will be under sanitized once the DMH reaches any appreciable level.

P.S. I do appreciate the way you constantly reiterate my warnings about TSP substitutes vs. TSP (and the fact that real TSP is not readily available in many areas in efforts to limit phosphate pollution in groundwaters (something I know a bit about, having been involved in research in oceanographic P. Chem in the 70's on the effects of various ions, including phosphates, on the precipitation and nucleation of calcium carbonate from seawater and seawaterlike solutions), having a second set of cart filters so they can be rotated while one set is soaking, and adding borates to 50 ppm! I wonder where you first read about these things?

You have certainly written many posts that contain technical details that have educated many service people. Many customers are getting much better service from professionals who have read your posts and applied the knowledge.

I don't have any problem giving you credit for your extensive contributions, as I noted above. I have read many of your posts, and I have learned a lot from them. Your posts are so numerous and comprehensive that would be difficult to give you the credit you deserve. There really isn't too much that you haven't covered. Anyone giving advice about pools or spas on the boards should probably acknowledge that they routinely use your advice.

That being said, I have been doing this for quite a while, so I do know quite a bit about these things. I have plenty of experience, and I do a lot of research. I have known about borates since Proteam first came out. Having a second set of filters is common knowledge for many people in the industry. I do acknowledge that your posts have helped in many areas, but they are only one of many sources.

[waterbear]

You leave out that I also have a background in chemistry.

The poster notes that they have a background in chemistry and a chemistry degree. Therefore, I think that they would have an interest in the chemistry involved.

While it is known that dimethylhydantion does make bromine "permanent" and not destroyed by sunlight there is no empirical evidence that, under normal usage such as I outline in the post quoted by gman will cause 'overstabiliizaton' as an excess of cyanuric acid does in a chlorine system. If you have evidence to the contrary I would be most interested in seeing it so please post the links. Thanks!

DMH below a maximum of 200 mg/L.

http://www.health.vi...ire_council.pdf

I see no reference at all in this one. Perhaps you have a wrong link?

The level of dimethylhydantoin in the water must be limited and should not exceed 200 mg/l. There is no poolside test kit available, and the need to regularly monitor dimethylhydantoin by a qualified laboratory is a disadvantage of the use of BCDMH.

http://www.who.int/w.../srwe2chap5.pdf

Where bromochlorodimethylhydantoin is used, the maximum dimethylhydantoin concentration shall be 200 mg/L.

Reference

Here is what I said:

The only problem is that we do not know how much of an effect the DMH has on the bromine.

My opinion is that until we know for sure the accurate equilibrium equations, we should try to minimize the amount of DMH. It is safer to minimize than not. The above references indicate 200 ppm as the recommended upper limit. I assume that they have reasons and evidence to support their advice. I think that a hot tub that relies heavily on bromine tabs and has high usage could exceed 200 ppm in a 4 month period. Further, if the DMH does have even a fraction of the effect of cyanuric acid, then unless one maintains a proper ratio, the tub will be under sanitized once the DMH reaches any appreciable level.

I would be more interested in the research that formed the opinion that 200 ppm is the upper limit for DMH rather than a brief sentence that it should be limited to 200 ppm. It is much the same as where they are saying that CYA should be limited to 100 ppm in one of the above links and we know the actual reality is more complex than that. Once again empirical evidence suggests that with a 3-4 month water change a three step bromine system functions well. I suspect that their recommendation is for a one step bromine only using DBDMH and related chemicals, which we know is not a good idea for several reasons, least of which is that, until there is enough bromide ions in the water to create the 'bank' (which can take weeks with slow dissolving tabs) the water is not properly sanitized.

P.S. I do appreciate the way you constantly reiterate my warnings about TSP substitutes vs. TSP (and the fact that real TSP is not readily available in many areas in efforts to limit phosphate pollution in groundwaters (something I know a bit about, having been involved in research in oceanographic P. Chem in the 70's on the effects of various ions, including phosphates, on the precipitation and nucleation of calcium carbonate from seawater and seawaterlike solutions), having a second set of cart filters so they can be rotated while one set is soaking, and adding borates to 50 ppm! I wonder where you first read about these things?

You have certainly written many posts that contain technical details that have educated many service people. Many customers are getting much better service from professionals who have read your posts and applied the knowledge.

I don't have any problem giving you credit for your extensive contributions, as I noted above. I have read many of your posts, and I have learned a lot from them. Your posts are so numerous and comprehensive that would be difficult to give you the credit you deserve. There really isn't too much that you haven't covered. Anyone giving advice about pools or spas on the boards should probably acknowledge that they routinely use your advice.

That being said, I have been doing this for quite a while, so I do know quite a bit about these things. I have plenty of experience, and I do a lot of research. I have known about borates since Proteam first came out.

Yes, and John Girvan had the test pools here in N. Florida before Proteam was bought out by Haviland.

Having a second set of filters is common knowledge for many people in the industry.

Granted. This really is common knowledge that many people do not do so it bears repeating again and again.

I do acknowledge that your posts have helped in many areas, but they are only one of many sources.

I do not disagree.

My point, and if you work in the industry you know it's true, is that the info has to be in a form that is easily comprehended by the average pool or spa owner. There is a time and place for detailed chemical discussions but, IMHO, it is not in a thread where basic info is being asked for, even if the OP states they have a chemistry background but it is evident from what they post that they do not have knowledge of pool/spa water chemistry, which is a specialized area as you well know.

I've said it before and I will say it now

K.I.S.S.

Pool and spa care is really not difficult to do properly under real life conditions and THAT is the message we need to be getting out instead of making it seem to be something that requires an advanced degree in chemistry and a full laboratory at our disposal to achieve clean, safe water.

[quantumchromodynamics]

I see no reference at all in this one. Perhaps you have a wrong link?

It's in there. Since it's a pdf, you can use the "find" box. Enter DMH in the find box. It's on page 3.

Reference

CYA should be limited to 100 ppm in one of the above links and we know the actual reality is more complex than that.

That's partly my point. The 200 ppm limit suggests that there is a similar relationship between bromine and DMH as there is with chlorine and cyanuric acid. Without knowing how much of an effect the DMH has, I think that the most conservative thing to do is to minimize it as much as reasonably possible.

My point, and if you work in the industry you know it's true, is that the info has to be in a form that is easily comprehended by the average pool or spa owner.

And, my point is that it's not just average pool and spa owners that read the posts. There are many people who are able to comprehend the details and want to know.

Pool and spa care is really not difficult to do properly under real life conditions and THAT is the message we need to be getting out instead of making it seem to be something that requires an advanced degree in chemistry and a full laboratory at our disposal to achieve clean, safe water.

There is an easy way to do anything; the hard part is finding the easy way.

I do understand your point. The problem is that there are many people giving people easy answers, and people are getting poor results. The poster was given an easy routine, and ended up with nasty water. If someone is lucky enough to get advice from someone like you who knows exactly what they are doing, then they will get good results. But, how do they know who knows what they're doing, and who doesn't?

There are many easy routines, but only a few good ones. You know which ones are good because you understand the science and chemistry behind the routine.

I feel that by giving a more thorough, detailed scientific answer people can make better, more informed decisions and get better overall results. I don't like doing things just because someone says that it is the way to do it. I want to know why, and I feel like many others also feel the same way.

Of course, people always have the option of skipping the post if they feel that it is more than they want to deal with.

[quantumchromodynamics]

I would be more interested in the research that formed the opinion that 200 ppm is the upper limit for DMH rather than a brief sentence that it should be limited to 200 ppm.

Hmmm...interesting. Here is someone giving an easy answer, and you're like "Hey, wait a minute. That's not good enough. That's not acceptable. I want to see the research that backs up their opinion about the 200 mg/l limit."

Notice that you refer to it as their "opinion", not as a fact. You are not willing to accept it until you see the chemistry for yourself. You find it deeply unsatisfying that someone just gives an answer without providing any explanation or science. This proves my point.

[waterbear]

I would be more interested in the research that formed the opinion that 200 ppm is the upper limit for DMH rather than a brief sentence that it should be limited to 200 ppm.

Hmmm...interesting. Here is someone giving an easy answer, and you're like "Hey, wait a minute. That's not good enough. That's not acceptable. I want to see the research that backs up their opinion about the 200 mg/l limit."

Notice that you refer to it as their "opinion", not as a fact. You are not willing to accept it until you see the chemistry for yourself. You find it deeply unsatisfying that someone just gives an answer without providing any explanation or science. This proves my point.

I really don't understand why you persist so. You repeat almost verbatim chemistry that others have posted time and again and take little bits of info and hang on to them for dear life instead of seeing the big picture. It's just water after all. Personally I do like to see the chemistry and science behind it all but my talent is taking that technical info and breaking it down into a step by step that is easy to do and understand., be it explaining how to maintain a bromine spa or explaining a difficult concept such as what is the bicarbonate buffer system we call TA and how it works. THAT is why so many refer to my posts that I have made over the years on pool and spa care. In the proper venue I will gladly discuss hard core chemistry (and I have on numerous occasions) but once again I reiterate that I do not feel it is appropriate in a general post on spa care.

If you would care to start a thread on DMH and it's effects we can discuss it there. As far as comparing DMH to CYA, there a a lot of empirical evidence and also scientific research that I have seen backing up the cautions about CYA and overstabilization. That info does not seem to exist for DBDMH and the empirical evidence indicates that, at least in spas that have routine water changes, it is not a major issue. I would think it would be more of an issue in pools, which do not normally have their water changed but bromine would not be my first choice sanitizer for a pool, particularly an outdoor one, since while DMH might keep bromine from becoming inactive bromate there is no evidence that it protects bromine from UV degradation that I have been able to find. If you have such info I would be very interested in seeing it.

[quantumchromodynamics]

High concentrations of dimethyl hydantoin (the DMH in BCDMH) are known to build up in pools treated with bromo-chloro-dimethylhydantoin, tying up bromine and reducing effectiveness. Problems similar to those that occur in chlorinated pools overstabilized with cyanuric acid result. Oxidation reduction potential (ORP) levels plummet as the brominated pool water ages. The minimum 750 mV ORP levels often become difficult to reach.

In a study conducted by Olin Chemical of commercial pools using BCDMH (Technical Bulletin "Bromine Use in Swimming Pools: Exploding the Myths"), results showed that the concentration of organics was three times higher than that typically found in chlorinated pools, DMH levels were elevated, more than half the bromine measured by DPD total bromine test kits was bromamine rather than free bromine, and the pools reported continuing problems with cloudiness and bather skin irritation.

Reference

The dimethylhydantoin in the tablets seems to have a similar (but not identical) function in a bromine system as CYA does in a chlorine system. It tends to stabilize it but, like CYA, too much is not good.

Reference

Like chlorine, unstabilized bromine is 90% decomposed by sunlight in 3 h. Polarographic studies show that cyanuric acid (CA) reacts with free bromine (ie, HOBr and BrO) forming bromoisocyanurates, which improves stability at sufficiently high CA concentrations, but not as effectively as stabilization of chlorine (9). Dimethylhydantoin, the parent compound of BCDMH, provides better stability, but still not equivalent to stabilization of chlorine by CA (9).

9. J. A. Wojtowicz,J. Sw. Pool and Spa Ind.4(1), 9 (2001);5(1), 19 (2004); B. B. San- del, Olin Corp., unpublished Data on Testing of Copper-Silver Cartridge, 1992.

Kirk-Othmer Encyclopedia of Chemical Technology

Reference

As the chlorine and bromine in BCDMH are used up the amount of the DMH part of the chemical in the pool increases. Excessive DMH affects the disinfection efficiency so the level must not be allowed to get too high. The concentration should not exceed 200 ppm.

http://www.swimming-pool-chemicals.co.uk/sp-water-chemicals.html

Facilities using bromine as a sanitiser shall keep the DMH levels no greater than 200 milligrams per litre.

http://cat1.poolsafety.com.au/uploaddocs/Code_of_Practice_Aquatic_Facilities%20May%202010.pdf

Dimethylhydantoin (DMH) is a disinfection by-product of BCDMH, which has been associated with skin irritation (bromine itch) when the DMH concentration in pool water becomes too high. Pool operators need to maintain DMH below 200 mg/L. This is achieved by frequent backwashing and dilution with fresh water.

Heavily used spa pools within high-risk premises (such as nursing homes) should be emptied and cleaned weekly. Spa pools which are infrequently used and well maintained are likely to maintain good water quality and therefore could be emptied less frequently (maximum three months).

http://www.health.nsw.gov.au/resources/publichealth/environment/water/pdf/code_of_practice_swimming_pool.pdf

Bromine, like chlorine, may be degraded by sunlight. The carrier compound of BCDMH and DBDMH, the dimethylhydantoin (DMH), has been found to protect the bromine residual from sunlight. However, that protection is much less than the protection cyanuric acid gives to chlorine.

Reference

[Hotsprung]

Whoa.... My head hurts!

Chemtexx, have you managed to get rid of the smell yet?

[quantumchromodynamics]

You repeat almost verbatim chemistry that others have posted time and again

Here is my most recent post with chemistry information. Post a link to anyone who has said the same or similar thing.

Dimethylhydantoin has a pKa of 9.19. Here are the correction factors for DMH:

pH........% DMH

7.0..........0.251

7.1..........0.315

7.2..........0.396

7.3..........0.497

7.4..........0.623

7.5..........0.78

7.6..........0.98

7.7..........1.22

7.8..........1.53

7.9..........1.91

8.0..........2.37

For example, at a pH of 7.9 and a DMH level of 200 ppm, the DMH will contribute 3.82 ppm to the TA.

How much of the chemistry information that you post is a result of your original research? What chemistry information have you posted that has not been posted by others?

[Roger]

Forget about all the crap spewed above. Use a little diclor to sanitize after use. Baking soda or lemon juice to adjust PH and call it good.

[waterbear]

. Baking soda or lemon juice to adjust PH and call it good.

this is not good advice