Safe swimming with elevated chlorine

[fcfrey]

There is a controversy regarding the "Safe" Chlorine level for swimming.

Most of what I have read says below 5 ppm otherwise chlorine can be absorbed through the skin and is hazardous to your health.

The rub comes when the CYA level is above 50 it takes a higher level (6 to 15 ppm) of free chlorine to sanitize.

HELP!!!

My bathing suit fading is minor compared to health problems from chlorine being absorbed while I'm swimming in a sanitized pool.

[CarlD]

There is a controversy regarding the "Safe" Chlorine level for swimming.

Most of what I have read says below 5 ppm otherwise chlorine can be absorbed through the skin and is hazardous to your health.

The rub comes when the CYA level is above 50 it takes a higher level (6 to 15 ppm) of free chlorine to sanitize.

HELP!!!

My bathing suit fading is minor compared to health problems from chlorine being absorbed while I'm swimming in a sanitized pool.

No controversy HERE! We think those other sites are full of beans--and we have the evidence to back it up.

"Safe" levels from government agencies and such are frequently contradictory--it's not safe to swim in water with FC > 3ppm, but it's safe to DRINK water with FC = 4ppm...See what I mean? It just doesn't make sense.

On Ben's PoolSolutions.com web site is an article documenting what happened in Parugway when they stopped using chlorine in drinking water to reduce chlorine related cancers. It worked, but the number of water borne disease deaths jumped to TEN TIMES what the chlorine hazard had been--and the incidents of water-borne diseases became epidemic. So are you more concerned about a VERY low risk from chlorine, or an almost CERTAIN risk from unsanitary water.

My choice is to take the chlorine risk.

[fcfrey]

Thanks Carl,
I hope you're not ready to have this moved to the "China Shop" but it seems to me like there are an awful lot of agencies and internet sites that make the recommendation NOT to swim in pools with an elevated cl level.

Waterbear was pinned down in his post "Smell chlorine w/ 0 cc?" to say go ahead and have 20 kids swim with a cl level up around 22 ppm. Again in your response "Best FC levels to swim?" “If you must swim in the higher FC levels, be sure to wear older bathing suits as they may fade.” ------ My response is ---- Are these responsible answers to people who accept the answers as “gospel”?!

I have read the article on Ben's site about Paraguay and agree that not using cl has a huge downside, but to compare a third world South American country's drinking water supply to our pools seems like a stretch.

In using that article to justify swimming in a 20+ ppm chlorine swimming pool we may very possibly be putting our families and guests at risk and vulnerable to liabilities I’m not ready to accept.

See these links: ----- and many many more.
http://www.health.sa.gov.au/pehs/topics/topic-private-pools.htm
http://www.waterandhealth.org/healthy_pools/healthy_pools_faq.html
http://www.waterandhealth.org/newsletter/pool_health.html
http://c3.org/chlorine_knowledge_center/pools.html
http://www.thegreenguide.com/doc.mhtml?i=ask&s=pools

[CarlD]

I dunno...only the greenguide deviated substantially from our recs.

And they are more concerned with the chemical risks of chlorine than the biological health risks of NO chlorine.

In NO case did they look at chlorine levels while controling for CYA levels.

[waterbear]

Waterbear was pinned down in his post "Smell chlorine w/ 0 cc?" to say go ahead and have 20 kids swim with a cl level up around 22 ppm. Again in your response "Best FC levels to swim?" “If you must swim in the higher FC levels, be sure to wear older bathing suits as they may fade.” ------ My response is ---- Are these responsible answers to people who accept the answers as “gospel”?!


Exactly how was I 'Pinned Down"? If you reread through the thread you will see that I said it depends on the CYA level. As far as what is acceptable...Here in the state of Florida a commercial pool can be open when the FC is 10 ppm or less. This is also in the new edition of the CPO handbook. This is a big change from a short while ago when the FC had to be 3 ppm or less! Commercial pools are also shut down when the CYA reaches 100 ppm but ask most pool stores and chlorine manufacturers if you can swim in a pool with more than 100 ppm CYA and they will say yes! If the CYA levels are high you NEED higher FC levels to have enough active sanitizer in the water.

I told Madty not to swim if he/she was still shocking the pool and there was algae present. Also when he/she said his CYA was 28 I said to wait for a good sunny day to burn off some of the chlorine! This poster seemed determined to let the kids swim while still fighting algae in the pool after I said not to.
If you are going to use my name please get your facts straight!

[fcfrey]

First of all – My post was not intended as a “flame”. If I offended anyone, my apologies.

My intent was to open a dialog on a subject that seems to be very illusive. No one appears to be willing to back up their belief with hard scientific facts or evidence from the people who have the knowledge to say one way or the other.

Of the 4 sites I posted all mentioned to maintain a 1-3 or 4 ppm FC. The Australian site went on to say not to enter the pool if the CL level was above 4mg/L, if my math is correct that equates to 4 ppm. Several other sites not sited in my post say 5 ppm max. Admittedly they do not mention CYA levels ---- Why is that??? Perhaps it doesn’t matter in the context of their statements. Perhaps they don’t know any better. I do not know.

Believe me ---- I want to swim every available opportunity, but if we have shocked recently and the cl level is still high, I find it difficult to justify, or convince my wife, that it is safe.

[Madty]

Hey- I did ask about high chlorine and looked at many websites. Above 30 was were it started to become dangerous as far as irrated eyes and respitory(sp) problems. At 50 there were more dangers. At 1000 you can die within 5 minutes. Kid swam at my house when it was 20. I told all of the parents of any unknown risks and let them decide. Most kids had goggles. The one's that didn't had hurting eyes- After a couple of hours and eyedrops, all was ok. There is soooo much different information out there. Today it was 16 and no one swam- I will not let anyone until we get down to 5 or so. I have turned off my swg and the cl only dropped 4 from yesterday. Also, most of the high cl problems dealt with indoor pools that aren't well ventilated. I remember as a kid on swimteams finding it hard to breathe in deep after swimming inside all day. It would almost feel like you had a sore throat, and it took your breath away.

[fcfrey]

Thanks Madty,

Sounds like your looking for the same thing I am ---- definitive answers!!

I sent an email to the 3c site I posted. We'll see if they answer. I will post the answer if I'm not black-balled.

As you can see I got red mark --- I guess for dissent :mad: --- I guess I better let that go!!:confused:

[CarlD]

Any member can post a black mark against another--click on the scales on the right and you can rate THAT person at that moment. It doesn't necessarily come down from the administration.

[waterbear]

If I let the number of negative reputations that I've gotten upset me I would not be an active member of this forum. I just got one for a posting in a thread about filter sand but I was the only one that was able to provide any advice that actually helped the starter of the thread even though my advice went againts the beliefs of some of the Mods and Ben. Everyone else that posted in the thread just just kept asking, 'why do you think you have this problem?' It's just a way for people to express their opinions...not a big deal! Getting back to the topic of this thread. There is a lot of conflicting info about chlorine levels. Until very recently 1 ppm was considered enough. Now in many areas 2 ppm is the minimun for a commercial pool becase of new research on kill times for some water born illnesses. As far as maximum levels, that depends on the local health departments. I believe Texas has an upper limit of 8 ppm and if I am not mistaken Hawaii is 5 ppm. None of these take into account the CYA levels which are ususally permissable up to 100 ppm and most recommend a level of about 40 for outdoor pools from what I have seen. One commen requirement is an ORP reading of 650 mv if an ORP sensor is used. It is a known fact that higher FC levels are necessary at higher CYA levels to obtain an ORP reading of 650 MV....much in line with Ben's 'best guess' CYA chart. IF htere is no CYA in a pool then the 650mv ORP reading is obtainable with 1-3 ppm FC. As soon as CYA is introduced into the water a higher FC level is needed to obtain the 650 mv reading.

[cygnusecks]

I doubt anyone will say "yes, definitely, swim in 20ppm, no problem, you'll never get sick". These kinds of absolutes rarely exist (notice I say rarely instead of never). Never say never, that's the first rule of lawyer club!!

[cheshamjim]

Someone posted this (http://www.ppoa.org/pdfs/PrP_Cyanurics%20-%20Benefactor%20or%20Bomb.pdf) on another thread recently. Seems like a really good article on the relationship of CYA and chlorine. It explains ORP (oxidation reduction potential) and references academic studies on this subject.

I was curious earlier whether the bad effects of high chlorine were somehow reduced in a high CYA pool, so I started a thread on the subject.

I am a believer in Ben's Best Guess chart and dose my pool accordingly, but I also appreciate the questioning of fcfrey. It contributes and keeps us honest.

edit: ...and prompts a pretty good post from PoolDoc.:)

-Jim

[PoolDoc]

Hi All;

First, I am moving this thread to the China Shop -- which is NOT an indication that I disapprove of the question, or the discussion. It simply reflects that this thread is a debate about somewhat theoretical issues, rather than an answer to a practical question.

I'm sure it's my fault, but there seems to be a perception of the China Shop as the near equivalent of the Hall of Shame. Thhere's no such equivalence in my mind. My intention is that the China Shop is where answers should be hashed out, where a clear one doesn't exist, OR where someone is unconvinced. To some degree, both issues exist within this thread.

----------------------------------------------------------------

However, to return to the original issue . . .

The cited article from the Green Guide is actually one of the best and most informative of the citations mentioned above. The others seem to be 'me-too' articles, without footnotes or reference to research. To the best of my knowledge, the Green Guide article accurately, but incompletely, reports on some issues regarding chlorination. Unfortunately, the articlet fails to place that information within the appropriate context. I don't know that this was a deliberate effort on the part of the authors, or an oversight on their part. But have seen a consistent lack of 'contextualization' in articles by environmentalists about chlorine. Many of them have a structure somewhat like this:

The sky is falling, in Antartica, in maybe 600 years.

Still, I should quickly add, that the article is FAR less biased and FAR more accurate than what I've become accustomed to, when reading articles about chlorine by 'greenies'.

Let me see if I can address the issues in the article.

It is true that chlorine reacts badly with many organics, to form the sort of chemicals described. But several important points are omitted!

Dioxin and furans have NOT -- to the best of my knowledge -- been identified as forming when relatively clean water (like pool water) is chlorinated. Rather, they form when industrial waste or process streams are chlorinated. Thus, while these chemicals may (and there's considerable doubt about just how toxic dioxins, in particular, really are!) be an important issue, they are not, to the best of my knowledge, a pool issue. To omit this information is fundamentally misleading.

However, it is true that some noxious chlorinated organics do form when pools are chlorinated. It's also true that there's a growing body of evidence that indoor pools are increasingly not so good for asthmatics, and may even lead to the emergence of asthma in previously healthy individuals. This is an issue that is very important to me. My oldest son nearly died of asthma when he was 3 years old. Now, at 19, his asthma is very well controlled, but he must take several medications daily. He began swimming at 4 or 5 years old, as part of regimen we stayed on, to protect his health. At 15, he was an elite distance swimmer, and was approaching sub-17 minute mile times. But, at 16 he dropped out of USS swimming, because the affects of the asthma prevented him from moving to the next level in competition. Now, at 19, he teaches swimming 4 days per week and swims 3 - 5 per week with the local master's group. He recently entered his first open water competitive swim, and was the overall winner of the 4 1/2 mile event, and the lack of chlorinated organics in the air definitely helped his performance.

Anyhow, I've pursued information about swimming, pool room IAQ, and respiratory effects for years for reasons that had little to do with the PoolForum. Unfortunately, that much of that data is of very poor quality. Often, the studies are done EITHER by physicians or ELSE by engineers. The result tends to be that the studies either have very good data on physiologic effects of exposure to particular pool environments OR they have good data characterizing the chemical and environmental parameters of particular pool environments, but not both. The doctors tend to do a poor job of quantifying what's in the water or the air, often lumping all oxidizing halogen compounds under the label, "Chlorine". And, the engineers tend to do a poor job examing the health effects of exposure, and fail both to establish control groups and to carefully and accurately assess both pre- and post-exposure subject health status. All the analyses tend to suffer for a lack of specificity in identifying the various species of DBP present, even though such specificity is very important to understanding the risks and reducing the problem contaminants. The barrier is that exact analysis of these compounds is both difficult and expensive.

Going futher, the "Green Guide" observes that some of these DBP's (Disinfection By-Products) "biodegrade very slowly". While this may, or may not be true, it is stunningly IRRELEVANT to pool operators and swimmers, since biodegradation NEVER occurs in properly operated swimming pools! Properly operated pools have no microbes present to biodegrade anything, either slowly or rapidly!

Nevertheless, I know from my own son's experience, and from that of many other asthmatic swimmers, that the IAQ (Indoor Air Quality) of many competitive pools adversely affected him, and other swimmers as well. With certain pools -- particularly including the Tracy Caulkins pool in Nashville -- we learned to keep him entirely out of the facility, except when he had to be there for his events. Even then we gave up on the 4th day for 4 day meets: the air quality would be so bad that his performance was always poor. His best times always came at certain pools that had very good IAQ, such as the old pool at the University of Tennesse at Knoxville.

But, again, the "Green Guide" omitted a crucial piece of data. While it is true that there's growing evidence that chlorinated pools may be adversely affecting respiratory functions, especially among asthmatics, this data UNIVERSALLY applies EXCLUSIVELY to INDOOR pools!

To the best of my knowledge, there is NO EVIDENCE whatsoever of similar effects from swimming in outdoor pools!

Indoor pools, as I have said many times before, are an entirely different matter than outdoor pools, and much harder to 'do right'. For years now, I've deliberately avoided discussions here of managing indoor pool chemistry, for precisely that reason. I have, personally, years of experience with such pools. And it's precisely that experience that has convinced me that there are no 'easy answers' for indoor pool operators, corresponding to the answers I can offer outdoor pool operators.

The bottom line is that there are problems with DBP's and THM (Tri-Halo-Methanes) which form when indoor pools are chlorinated. There is a growing body of evidence that these complex halogenated volatile compounds adversely affect swimmer respiratory function. BUT, this data has virtually NO relevance for the PoolForum user population, which is almost exclusively composed of owners of OUTDOOR RESIDENTIAL pools, which not only have unlimited 'ventilation' with fresh air, but which are further exposed to solar UV, and subject to photolytic degradation of those DBP's. Both chloroform and bromodichloromethane are known to be photolytically degraded; my guess is that many of the other DBP's are as well. This of course will dramatically affect any potential *build-up* of these compounds in *outdoor* pools.

In the "Green Guide" article, you may recall that the question the author, Carmela M. Federico, purports to answer was this: "Is Chlorine Safe For My Pool?". She proceeds to report, more or less accurately, on hazards that may result from the chlorination of *industrial process or waste streams* and *indoor* pools. Since less than 1% of pool owners have indoor pools, and since 0% of pool users are swimming in either waste or process streams . . . she really didn't have anything to say of relevance for the 99% of pool owners who have *outdoor* pools.

More pointedly, even in what she did say, she said NOTHING about what SPECIFIC levels of chlorine were safe or unsafe, which was the heart of the question posed by the OP.

Even more negligently, she recommends, in rather vague fashion, trying to induce health departments to drop chlorine, but fails utterly to consider the health risk of doing so! This is seriously irresponsible. As is disgustingly common in such articles, the author doesn't address, even briefly, the reasons chlorine is added to the water in the first place, nor does she acknowledge the huge and unprecedented IMPROVEMENT in public health brought about by the chlorination of water. Please keep in mind that it is arguable that chlorination of drinking water has saved more lives than the entire medical care system!

Her recommendation to use other, vaguely specified, non-chlorine methods has a very definite -- and not particularly small -- risk to the health of those using waters treated with such methods!

So, even though many of the details in her article were accurate, the overall picture she presented was so degraded by a lack of context, and by magician-like misdirection, as to create an almost completely false representation of the situation faced by most pool owners!

. . . continued next


Ben
"PoolDoc"

[PoolDoc]

. . . continued from above

The other articles were much less informative, and mostly contained 'me-too' recitations of the standard pool industry wisdom. Most of what I say was correct. However, the specific chlorine level guidelines listed were either unsupported, or based on WAG's (Wild A## Guesses). Apparently so was the original (circa 1970) EPA standard of 3 ppm, according to reports I've gotten from people who were sitting at that table. What was reported to me was that they based their decision on the fact that most public pools, then using gas chlorine injected into pool water containing no stabilizer, were struggling to maintain 1 ppm, but that those that did were mostly achieving what was then perceived to be adequate sanitation. The 3 ppm level was reportedly chosen as been sufficiently greater than the common 1 ppm, to offer an adequate range of operation. The problem was that this 3 ppm standard is NOT appropriate for the stabilized pool operations that was just beginning to be widespread at that time.


By the way, I found one very informative analysis posted on the web, in checking out some things for this post. In particular, it may be right up Waterbear's alley. Here's where I found it: http://almashriq.hiof.no/lebanon/600/610/614/solar-water/idrc/

That's all for now . . .

Ben
"PoolDoc"

[PoolDoc]

Most of what I have read says below 5 ppm otherwise chlorine can be absorbed through the skin and is hazardous to your health.


Just one correction to your comment: as far as I know, it is entirely FALSE that "chlorine can be absorbed through the skin". Rather there is evidence that some halogenated compounds -- which may, or may not be present in pools -- can be so absorbed.

But keep in mind that salt is a halogen compound, as is your pool liner, as are many other ubiquitous materials.

Ben

[waterbear]

By the way, I found one very informative analysis posted on the web, in checking out some things for this post. In particular, it may be right up Waterbear's alley. Here's where I found it: http://almashriq.hiof.no/lebanon/600/610/614/solar-water/idrc/

That's all for now . . .

Ben
"PoolDoc" Very intersting reading. The germacidal properties of sunlight and UV are well known. The most pertinent things I got from the paper are some things that we already know....Sunlight (mostly UVB) destroys simple halogens and might also destroy combined ones. Interesting side note, As I've said before I've kept aquariums for many years and when choramines became commen in drinking water treatement to prevent the formation of trihalomethanes it became a real pain in the a** to treat the water to get rid of the chloramines and the chorine. When chlorine by itself was used it only took a bit of sodium thiosulfate to destroy the chlorine and make the water safe for the tank. When chloramines were in the water we had to resort to breakpoint chlorination first and then thiosulfate....or as an alternative, it was determined that leaving the water exposed to direct sunlight for a day or two would destroy most of the choramines. OTO was the recommened test to determine when the chlorine was gone in either method. Not sure who came up with the sunlight method but it was pretty popular in my circle in the late 70's. It was discussed at the Marine Aquaruim Society that I belonged to at meetings.

Getting back to the article. From my understanding it's main thrust was what they call the 'Halisol" method which uses halogen compounds and then UVB from sunlight which continue the sanitation and also destroy the halogens and possibly the combined halogens that form.. It would then seem to support what Ben said about outdoor pools. The bad stuff gets burned off by the sun (along with the good chlorine). To carry it one step further, if one is concerned about the health effects of chlorine in their pool then adding a UV unit could reduce the levels and also have a germicidal effect. Pretty much the claims made for UV units. Downside is the destruction of the necessary residual sanitizer.

I found the wavelengths that were effective intersting....once again from my experiences with aquariums. UV units for aquariums usually peak about 280 angstroms... UVC/UVB light. I have used them and gave up on them. Never really saw any benifits. The article stated that most of the UV that came from through the atmosphere was in the 320 -400 range...UVA. Marine aquariums use a type of bulb known as an 'actinic' bulb which produces light in the 440 angstrom range but also produces a lot of light in the UVA range and many aquariums also use metal halide bulbs which produce a lot of UVB/UVA light. I have seen higher redox readings on aquariums with this type of lighting (used in reef tanks) than with standard lightling. However, algae thrives under this type of light but cyanobacteria do not. Don't really understand enough of what is going on chemically to explain it except that higher redox in an aqauarium promotes more green (good) algae and destroys red and bluegeen (bad) algae. Then again, the first type of algae that usually takes hold in a pool is green algae. I suspect this is connected to the redox potential of the water. As water quality deteriorates the redox potential lowers so green algae will appear when there is not enought FC to to kill it but there are still some oxidative processes going on (such as a pool with high CYA and 'normal' FC levels...sound familiar?). As these lessen the mustard and black algaes (related to the bluegeen algaes in tanks) take hold ( Usually when a pool has been neglected and there is no chlorine or the CYA levels have gotten sky high). Pure speculaton on my part...but food for thought!

Sorry I can't relate more of this to pools but I have a lot more experience with aquariums and the effects of lighting (and we try and get rid of halogens in the water before we put the livestock in!) However, oxidation is an important process in an aquarium and redox is an important measurement. We use UV, ozone, and even hydrogen peroxide to treat the water to oxidize ammonia compounds and organics, then rely on nitrifying bacteria to convert what is left to nitrates, and finally, on anerobic denitrifying bacteria to convert the nitrates back into nitrogen gas so it can leave the water. If the organics cannot be sufficienly oxidized first then the nitrate levels get very high and denitrification is not sufficient to keep the nitrate levels down.

One needs to understand that there is a difference between oxidation and disinfection. Oxidation occurs in an aquarium but many bacteria and algae thrive. This is why oxidation by itself is not adequite for a pool and, personally, makes me a bit suspect of relying on ORP controllers to determine proper sanitation levels. I am the first to admit that I don't know much about their application in pools firsthand but I do know that such chemicals as hydrogen peroxde, CYA, Oxone (MPS), and sodium percarbonate mess up ORP readings in pools (and test as TC on OTO and DPD tests). In fact, sodium percarbonate is no longer used as a non chlorine 'shock' for this very reason, since it was mainly used in commercial pools with ORP controllers (although it is sometimes pushed as a way to convert a biguinide pool to chlorine quickly).

I realized that is seems that I have drifted off topic but I really haven't. Disinfection is necessary in a pool. Chlorine is the best disinfectant that we have. Many of the studies on pool disinfection are based on ORP readings of 650 mv or higher to determine proper sanitation levels but there seems to be a general fallacy in this since many factors can influance the ORP reading but don't really have an impact on actual sanitation and kill times. I personally would be more concerend about the health effects of low chlorine levels than I would about higher ones! As far as how much chlorine is safe....I don't think anyone really knows from what I have been able to research. It all seems rather arbitrary. Even the selection of 650 mv for ORP readings is an aribitrary selection. Florida requires an even higher reading (I believe it is 850 mv, gonna have to check the CPO text at work).

[medvampire]

Evan
I think one of the reasons for the green algae growth under these lighting conditions is the refraction and absorbance of light in a liquid (water) as well as the refraction in the cell membrane. Particulate matter with in the water may also effect the transition of light with in the body of water.


As for chlorine’s health effects, I feel that inhalation is the greatest cause for concern (Pool doc has already coverd that one). The skin, being a selective membrane, can tolerate high levels of many materials depending on the transport material it is in. Our skin is selective in non isotonic solutions with exceptions that should not occur in a normal pool environment. I would have a greater concern if your pool is salted to an isotonic state.
Solutions that could cause posing through the skin usually cause cell damage and prevent more absorbance through the body in general. The toxins that do manage to cross the epidermal layer are usually long term toxins causing general damage to the DNA.
Before I get nailed I am speaking of the chemistry found in the normal residential pool setting.
I would much rather deal with the few free radicals I may encounter in the pool with the right chlorine balance than deal with the microbe nastiness you will encounter with out it.
Steve

[ShelleyAnn]

I just want you guys to know, I am watching this thread very closely, as I seem to be shocking (15-16ppm) more than not shocking these days due to the endless rain we've been having. Unless I get IN the pool to brush the sides it's not going to get done as I don't have the arm strength to brush the sides of our AGP from the outside.

Keep the facts/best guesses coming. Fascinating.

[waterbear]

Evan
I think one of the reasons for the green algae growth under these lighting conditions is the refraction and absorbance of light in a liquid (water) as well as the refraction in the cell membrane. Particulate matter with in the water may also effect the transition of light with in the body of water.
Actually, the type of algae that grows in a marine aquarium is directly related to the redox potential of the water! This has been documented time and again with ORP meters. With lower ORP readings there is predominently red and blue green algae growth (cyanobacteria) and brown and green algae disappear. As the redox potential rises the red and blue green disappear and brown algae forms (I believe it is related to the Mustard algae in our pools) and finally, as the redox potential rises up to about 450mv the brown disappears and green algae is the predominent form seen.

As for chlorine’s health effects, I feel that inhalation is the greatest cause for concern (Pool doc has already coverd that one).
And this is primarily a concern of indoor pools.
The skin, being a selective membrane, can tolerate high levels of many materials depending on the transport material it is in. Our skin is selective in non isotonic solutions with exceptions that should not occur in a normal pool environment. I would have a greater concern if your pool is salted to an isotonic state.
Such as the salinity found in a salt water pool with about 3000 ppm NaCl? Interesting. I believe this is still below the isotonic point but not sure how much.
Solutions that could cause posing through the skin usually cause cell damage and prevent more absorbance through the body in general. The toxins that do manage to cross the epidermal layer are usually long term toxins causing general damage to the DNA.
Before I get nailed I am speaking of the chemistry found in the normal residential pool setting.
I would much rather deal with the few free radicals I may encounter in the pool with the right chlorine balance than deal with the microbe nastiness you will encounter with out it.
Steve

On your last point I agree wholeheartedly 100%!

[CarlD]

You all have me scared! I'm gonna hide under the bed...no, wait, there's dust and OTHER inhalable particles there....:eek:

It's all about balancing and weighing risk. I prefer the risks of chlorine to the risks of water-borne diseases, viruses and other infections.

[VOLDADDY]

I'm not trying to bring politics into this thread, but this sure sounds like something Al Gore would come up with. Global warming and chlorinated pools will be the downfall of us all. Oh well, at least we can stay cooled off in the chlorinated pool until we are done in.

[medvampire]

Waterbear

Such as the salinity found in a salt water pool with about 3000 ppm NaCl? Interesting. I believe this is still below the isotonic point but not sure how much.


Well below isotonic. Isotonic would be around 9000 ppm if I am doing the math right.


Actually, the type of algae that grows in a marine aquarium is directly related to the redox potential of the water! This has been documented time and again with ORP meters. With lower ORP readings there is predominently red and blue green algae growth (cyanobacteria) and brown and green algae disappear. As the redox potential rises the red and blue green disappear and brown algae forms (I believe it is related to the Mustard algae in our pools) and finally, as the redox potential rises up to about 450mv the brown disappears and green algae is the predominent form seen.


So each has its best tolerance of oxydation in the cell membrane as well as the mitochondrial protien formation. I am still reading on the effects of chlorine on celluar structures. I have found a lot of material I still have to read. Yes, I do need to get a life:o

CarlD
How is the view from under the bed? Enjoyng the dust bunnies? Had to go to L.A. last year and seen some bunnies I would love to get under the bed with. :D

I just cant understand why some one would want to swim in a pool of filth. The pros here spell out the needed levels of chems in a system that works in daily use and theroy. The methods here are easy to follow and help is your keyboard away. I understand this method is not what the pool stores tell you but this method works.;)
Steve

[waterbear]

I just cant understand why some one would want to swim in a pool of filth. The pros here spell out the needed levels of chems in a system that works in daily use and theroy. The methods here are easy to follow and help is your keyboard away. I understand this method is not what the pool stores tell you but this method works.;)
Steve
Some pool stores DO use this method! (but we do it with liquid chlorine, alk increaser, and Proteam "Supreme" instead of bleach, baking soda, and borax. Something has to pay my salery!:D
(and we sell the liquid chlorne at $3.69 for a 2.5 gal refill of 12.5%...cheaper than the ultra bleach we sell....we're a large hardware store with a large and complete pool dept. Everything from chems to equipment and even AG pools!)

[medvampire]

Cool
The stores around here push the chems at you. The people here stare at me with gasp when I pour bleach in my pool. They are starting to come around and understand this method.
Steve

[CarlD]

I'm not trying to bring politics into this thread, but this sure sounds like something Al Gore would come up with. Global warming and chlorinated pools will be the downfall of us all. Oh well, at least we can stay cooled off in the chlorinated pool until we are done in.

Then don't bring politics into it. This is a discussion, in this thread, of measurable evidence and the interpretation thereof, not politically correct left or right check-list positions. Science is science, no matter how the political winds try to bend it to their position.

[VOLDADDY]

Then don't bring politics into it. This is a discussion, in this thread, of measurable evidence and the interpretation thereof, not politically correct left or right check-list positions. Science is science, no matter how the political winds try to bend it to their position.

Carl,

It was a joke. My apologies for trying to interject a little humor.

[PoolDoc]

Then don't bring politics into it. This is a discussion, in this thread, of measurable evidence and the interpretation thereof, not politically correct left or right check-list positions. Science is science, no matter how the political winds try to bend it to their position.


It was a joke. My apologies for trying to interject a little humor.

While I would like to avoid the politics -- these days they are just far too inflammable -- humor on this topic is not a bad thing.

Most of you guys here are among the more 'chemically' advance posters, so this is probably a good time and place to say what I want to say.

The fears that people bring to the PoolForum are not, for the most part, irrational fears. Rather they are a rational response to the persistent and hyped anti-chlorine hysteria shrieked out by modern environmentalists and uncritically parroted by the mass media. The environmentalists are being irrational, but the consumers here are not!

What I mean is, they are responding rationally to the information sources which they have! I don't know how things were in the past, but today's media generators range, as an overall group, from the scientifically illiterate to the functionally brain-dead. But, consumers don't know this.

I do; you may; but they don't!

More to the point, they don't have any contradicting information sources, at least till they arrive here. The pool industry isn't going to contradict them, at least not much, because chlorine fears power the sales of chlorine alternatives and blends and pool addititives. The mass media isn't going to contradict them -- even when they know better -- because hysteria and hyped fears draw an audience many times better than a calm and somewhat technical consideration.

So, consumers arrive here knowing that chlorine is dangerous and toxic; knowing that their lives are shortened by its presence in their water and pools, and knowing that the responsible thing to do is to minimize its use, if only they can find an affordable alternative.

For me, and for y'all here, understanding this is critical to understanding what sort of responses consumers, with all their rational chlorine fears, need to be given. A big part of what's needed is to respect their rationality -- I myself need to be reminded of this, because I find the chlorine hysteria so tiresome.

So, each of you, please remind yourselves that, as irrational as much of the anti-chlorine hysteria is in its origin, yet that those fears are an entirely rational response on the part of most of the newbies here.

Please also remember that, even among college graduates, it is only a tiny minority who have the training, of mind and habit, think critically and skeptically about this issue.
Most college educated adults have functional math skills at the level of 1st year algebra OR LESS.
Most college educated adults have no training whatsoever that allows them rank relative risks.
Most college educated adults will readily accept the statement, "No price is too high to pay to save a life". Nor will they be able to see any inconsistency between accepting that statement, and then declining to pay $1000 extra for side air bags on their new car.I could ramble on about why this is so, what I think about our education system, and so forth. But it's simply not relevant.

When they arrive here, most newbies are -- given the skills they have, and the information available to them -- acting rationally when they express fears about chlorine.

I need to, and you all need to respect that rationality, and help to redirect it by providing better information, and perhaps, better analytical skills.

Thanks,

Ben

[CarlD]

Ben:
I have to contradict you:
A small extreme portion of the environmentalists are anti-chlorine--but those people are against ANY chemical usage, as irrational as that sounds.

I like to think of myself as somewhat environmentally aware and responsible (Hey! MY pool is heated with sunshine--as "green" as it gets!) but I would never advocate dropping chlorine usage until a PROVABLE replacement of similar quality is available--and bromine ain't it!

[medvampire]

I will have to whole heartily agree with the pool doc on the media hype surrounding chlorine. When I came top this forum I had bought in to the Nature 2 hype hook and sinker. I was overjoyed at the prospect of just running a 0.5 ppm chlorine level and thinking it was the best thing for my future step kids. I was against the getting the pool at first because of the chemical exposure to my self and the kids. (DHMO:D )
Being the geek I am I started reading on the net about the Nature 2 and the use of chlorine for pools and stumbled upon this forum. Being skeptical by nature I thought the first reading I did while was a bunch of hog wash. I went home and thought about it (girl friend asked about the gear grinding noise and smoke:rolleyes: ) and the light flickered and begin to burn as the pieces came together.
Working in a medical lab I am constantly exposed to chemicals so I have to have a some what good understanding of the chemical hazards and effects of chemicals on various body systems. The media and environmental groups scream about the dangers of chlorine but what are the effects of the other pool chemical systems on the environment and the human body? Are these system totally non hazardous? I doubt these systems if capable of sanitizing pool water have no effect on these systems.
But that is just my humble 2 cents.

Thanks again for opening my mind to a better and safer way of protecting my family because bottom line here is to keep people from getting sick while having fun in a body of stagnet water. I do enjoy the side effect of glass like water with the sun dancing across the surface.

CarlD
Better living through chemistry.:D

Steve

[CarlD]

LOL!

Just remember Ben's rule: THE most dangerous chemical, by far in ANY pool is the di-hydrogen monoxide
.
.
.
.
the water;)

[waterbear]

Ben:
I have to contradict you:
A small extreme portion of the environmentalists are anti-chlorine--but those people are against ANY chemical usage, as irrational as that sounds.

I like to think of myself as somewhat environmentally aware and responsible (Hey! MY pool is heated with sunshine--as "green" as it gets!) but I would never advocate dropping chlorine usage until a PROVABLE replacement of similar quality is available--and bromine ain't it!
Come one Carl, bromine has it's place in pool/spa use (but not in an outdoor pool). Anyway, the problems with chlorine safety really apply to bromine pretty much also. Some of the organic bromamines are just as bad as the organic chloramines.

[PoolDoc]

Ben:
I have to contradict you:
A small extreme portion of the environmentalists are anti-chlorine--but those people are against ANY chemical usage, as irrational as that sounds.

Maybe that's been your experience, but mine has been quite different. The portion of environmentalists who are anti-chlorine has seemed to me neither small nor atypically extreme.

I'll offer this challenge to you: Try to find even TWO articles which are, overall, pro-chlorine and which are published anywhere on the net by any community, blog, or periodical which self-identifies as being 'environmentalist' in focus and values.



Come one Carl, bromine has it's place in pool/spa use (but not in an outdoor pool). Anyway, the problems with chlorine safety really apply to bromine pretty much also. Some of the organic bromamines are just as bad as the organic chloramines.
Waterbear, this winter ask me for some of the bromine literature I have.

I, for one, am not convinced that bromine has any real value for either pools or spas. And, I'm almost convinced that the use of BCDMH or any other source of bromine bound to dimethyl hydantoin should be strongly discouraged.

I very strongly suspect that bromine has gained its positive reputation purely based on the absence of information. My impression is that chlorine and its compounds are far better known and understood than are bromine and its compounds. It's also my impression that bromates, which form under many conditions if bromine is used in pools or appears in source water, is considered a more serious 'bad actor' than are many of the chlorine products.

Regarding bromamines, I've never been able to find *any* information on what sort of bromamines appear in pools and spas, nor have I ever found a study that substantiates the oft-repeated pool industry maxim that "bromamines, unlike chloramines are good sanitizers".

It's worth noting, that with the demise of Hydrotech (purchased by BioLab), and the death of Jock Hamilton (founder of United Chemicals), pro-bromine pool industry press seems to have diminished to a bare trickle. It makes me wonder if ANYONE, except those trying to sell it, ever thought it was a good idea.

Color me skeptical!

Ben

[CarlD]

Maybe that's been your experience, but mine has been quite different. The portion of environmentalists who are anti-chlorine has seemed to me neither small nor atypically extreme.

I'll offer this challenge to you: Try to find even TWO articles which are, overall, pro-chlorine and which are published anywhere on the net by any community, blog, or periodical which self-identifies as being 'environmentalist' in focus and values.

C'mon, Ben--that's a sucker bet and we both know it. The only people give a dang about chlorine in the environmental movement are those that worry about it. Others spend their time on hydrocarbons, water pollution, landfills, and smokestacks. In other words, all the writing about it is by those who CARE about it, and stay up nights worrying about it. Everyone else (which is most of them) have far, FAR bigger fish to fry. So they DON'T write about it--and why alienate part of your coalition? That's simply politics.

My mother's next door neighbor is one who worries about chlorine. But she also tossed out her stove because she doesn't believe food should be cooked. They live on raw fruits and vegetables, the children are VERY small for their age, they are being "home-schooled" (Hah! I doubt either can read--not to crack on home-schooling but the way THIS nut does it.) She's stunted their growth and their intellectual growth. To me, that's MY stereotypical view of an anti-chlorine fanatic.

[PoolDoc]

Carl,

I don't think it's a sucker bet -- I think you are conceding my point without realizing it. Actually, I think you are saying something worse than what I said!

Maybe I should say it this way:

"When environmentalists speak about chlorine, they engage in anti-chlorine hype. It's possible that not all environmentalists actually believe that stuff, but if they don't, they remaining silent, rather than standing up and objecting to the dishonesty or hype."

To say that "All environmentalists who talk about chlorine engage in dishonest hype" is not quite the same as my original statement, which was:

"Rather they (consumer fears) are a rational response to the persistent and hyped anti-chlorine hysteria shrieked out by modern environmentalists and uncritically parroted by the mass media. The environmentalists are being irrational, but the consumers here are not!",
but, it's close enough for 'government work'!

My original description groups those environmentalists who speak of chlorine into a pool of irrational hysterics. You really haven't challenged this. Instead, you have added that they are a minority, surrounded by a much larger group who are both rational enough to admit private or internally that their comrades are fools, and dishonest enough to go along with they hysteria in public!

I really don't see how that puts things in a better light. :rolleyes:

I would suggest that the term "environmentalist" is a politicized one, today, and has meanings of political association that go beyond simply caring for, and about, the natural world. My family and I probably care about, and enjoy the 'natural world' as much as almost anyone not professionally engaged with it. On vacation, we prefer and seek, the company of owls and otters, or sharks and sea stars, or streams and trees, over that of people and 'features'. You'd pretty much have to pay us -- a LOT! -- to go to a place like Las Vegas. My 19yr old son has volunteered well over 1,000 hours as a docent and invertibrate husbandry specialist at the Tennessee Aquarium. And so on. But, given the political and cultural meanings attached to the word today, we'd never call ourselves "environmentalists".

Unfortunately, many of the issues that the "environmentalist" political camp has made its own are based either on weak science or worse, on bogus science. In order to sustain the political goals, the "environmentalists" have had to make public dishonesty a habit and a tool. This is what you have essentially admitted.

I have personally, encountered this again and again. I won't go into the long version of these, but I've encountered this dishonesy, reflected in institutional positions adopted by the EPA, CDC and others with chlorine (of course!) with asbestos, and with DDT.

Even as we speak, people in Africa and Asia are dying of malaria because of the worldwide ban on DDT. This ban remains in force in spite of all the evidence exposing Rachel Carson's fraud, and refuting virtually all of the claims of environmental damage from DDT. The irony is that this continued ban is depends on the current -- not past -- dishonesty of EPA scientists and bureaucrats and their ilk in other agencies who won't step up to the plate and say, "Gee, we were wrong. We're sorry for all the people who died as a result. But, we're going to try to do the right thing now."

So, it seems to me, that to say what you said, that most environmentalists are silent in the face of anti-chlorine hysteria, not because they are themselves hysterical about chlorine, but because they are dishonest, is even worse than what I said!:eek:

Unfortunately, I think you are correct!:(

Ben

[CarlD]

My original description groups those environmentalists who speak of chlorine into a pool of irrational hysterics. You really haven't challenged this.

I don't challenge it at all, Ben. In I thought I had said almost the same thing.

But are their silent brethren immoral for not publiclly challenging it? Perhaps, but the concept of a COALITION is that you agree on big points and don't shatter the coalition on smaller ones. Frankly, the anti-chlorine crowd is a side-show, but to protect the coalition, the other folks let it be.

This is a normal condition in coalitions. You agree on the big stuff and don't sweat the small stuff. Otherwise, you fragment and nobody gets anything done. It's the art of politics, the art of compromise. You could have EXACTLY the same criticisms of the Christian Right, the Democratic Party, the Republican Party, and even the Libertarian Party.

Even that most virulent group, Islamic Jihadists who engage in suicide bombing are constantly in conflict amongst themselves over interpretations and the "correct" path. Hezbollah can't really get along with Al Qaeda or Hamas.

Are stupid things done consequently? Sure! Would DDT end misery in certain segments in Africa? Probably. But consider: Had DDT been used all these years I submit it would be as useless now as if it had been banned. 40 or 50 years of constant usage would have developed totally DDT-resistant strains of pests who would have supplanted their non-DDT resistant relatives.

Meanwhile, our current administration is ignoring the HIGHLY successful AIDS prevention programs in Africa that tout ABC: Abstinence, Be Faithful and use Condoms. In fact, they are attempting to undermine these very effective programs in favor of abstinence as the sole means of preventions. Isn't that EQUALLY damaging? And we know it's because a particular group with clout demands orthodoxy.

So to get to the point, to demand orthodoxy on every single issue for intellectual or religious purity is an unrealistic violation of that classic maxim of of politics: Politics is the Art of Compromise.

Would I sacrifice the Hudson River to pollution just to shut up the anti Chlorine crowd? No WAY! It's a question of priorities and reality.

[PoolDoc]

I don't challenge it at all, Ben. In I thought I had said almost the same thing.
OK.

I'm beginning to understand now. When I call someone a liar, in public discourse, I'm also saying that there's no more point talking to them, or listening to what they say.

You don't agree. I don't really understand how, or why, though.

From where I sit, there's no point talking to a known liar. If they say, "proved" or "science", you have to discount that by thinking to yourself, "most likely, yet another lie". Lying is not only usually immoral; perhaps more fundamentally, it is corrosive of meaning.

This is precisely the issue I have with the "natural" SWG and ionizer crowd: if they lie in some of their primary claims about their units, how am I or their customers to know that they aren't lying every time it's convenient for them.

From my point of view, once someone has been established to be a known, persistent and unrepentent liar . . . there's nothing more to say. Of all the things I value here on the forum, my reputation as a 'truth-teller', is what I value most. This is one reason I have the China Shop. Comfortable, or not, I'm committed to trying to acknowledge the truth whether it's what I thought be true or not.

If people on the forum can't trust me to acknowledge when I'm wrong, I cannot reasonably expect them to trust me when I say -- as I have said -- that I'm right in certain areas where almost everyone else in the pool industry is wrong.

Trust is earned only when the truth is told even when it's not convenient or comfortable. People who tell the truth only when it's convenient are, well, liars. The most their statements can do is suggest a locus for investigation; the fact that they are liars means that their statements themselves can never be trusted and never taken as evidence!

If I'm not willing to acknowledge proof that I'm wrong with respect to some (or all) of what I've said about pools, then I don't deserve the trust of the people here.

But, that which I apply to myself, I apply to environmentalists: if they won't support the liars in their midst; if they themselves will not acknowledge the lies themselves when confronted with the evidence . . . then to my mind they become liars themselves.

I can work with someone with whom I disagree, but I don't see how I can work easily with someone I know to be a liar.




So to get to the point, to demand orthodoxy on every single issue for intellectual or religious purity is an unrealistic violation of that classic maxim of of politics: Politics is the Art of Compromise.

Maybe. I grant that being truthful does not mean telling, in every situation, all the truths I could. Some things cannot be helpfully spoken, even if 'true'

But you've defined "Compromise" as acceptance of the public lies of your fellows. I will not accept that definition or your maxim, at least here.

I'll not debate ethics, philosophy, or religion; such things go too far to be considered here.

Rather, I'll simply say that this is my forum, and that, whatever you think outside the forum, the standard here is that statements must match reality, at least to the best of your knowledge.

I'm committed to this, and I've tried to behave in a way consistent with this. Maybe I've failed, but I've tried.

It's been very uncomfortable for me, and very embarrassing, to have posters describing publicly how I've screwed up PS234 kit shipments and the salt test. I *could* have buried those complaints easily enough, in a variety of ways. But the miserable truth is that I have screwed up PS234 kit shipments, and all those complaints posted here are valid (with a very few exceptions).

I believe that the truth matters.

So, whatever ethics people bring with them, nevertheless here, on this forum, when someone is proven to be a liar . . . there's hardly anything worse that can be said about them. If they are unable to accept, in their posts here, the standards here, then they cannot really participate in this community.

Here the standard must be that the truth rules, and that errors, embarrassing or not, must be acknowledged.

You write that I "cannot demand orthodoxy" . . . but I cannot see that I can demand anything less. The word simply means right (ortho) teaching (doxa). Right teaching means not only being right but also accepting correction when proven wrong. From the very beginning, right teaching, is precisely what PoolSolutions, and the PoolForum has been about.

Take that away, and as far as I'm concerned, nothing's left worth that's saving. At its very foundations, lying robs speech of all meaning. To tolerate it, much less to embrace it, is to accept the very destruction of all speaking and teaching.

If I do that here, then I allow the PoolForum to become yet another "Babel" of confusion and meaninglessness.


Sincerely,

Ben Powell

[CarlD]

Ben,
I'm not sure where you are going with this. I hope you are speaking generally and this is not an "ad hominem" reference to me.

It is your forum, but you have set up this China Shop as a place to debate ideas, haven't you? I certainly won't refrain from debate, here, in the China Shop. I will, however, try to keep away from specific political parties and positions, and from peoples' religions.

Do I disagree with the anti-chlorine crowd? Obviously! I don't think that can be reasonably questioned. Do I LIKE the idea that a coalition frequently must tolerate people who blather on about irrational idiocy? No. But that IS the nature of coalitions, like it or not.

But as I have TRIED to make clear, sometimes you have to tolerate the positions that you don't like to achieve something you value more. Cost-benefit analysis. Hold your nose.

You yourself pointed out the "Green" article that their facts were essentially correct--but they mis-used them and applied them to non-appropriate situations. That doesn't necessarily make them liars. Or it does, and then EVERY political party is nothing but liars, bending and selecting facts to fit their position

Now we need to isolate two very different concepts:
1) Science
2) Law

In science, facts and analysis are critical. You should, in fact, MUST consider all known facts. You may not engage in "reductionism"--the ignoring of inconvenient facts. To do so is unethical. This is true of the social sciences as well as the hard sciences.

In Law, all the rules are different. A criminal defense attorney's job is NOT to find the truth, but to provide the best defense for the client. To do less is unethical. For the defense attorney to seek evidence that will convict the client may be a pursuit of the truth, but then the accused has NOBODY to rely on--and this violates the presumption of innocence until PROVEN guilty.

The prosecution's job is SUPPOSED to be to seek the truth, but in fact, is to get convictions. The prosecutor is supposed to provide ALL evidence to the defense, exculpatory as well as incriminating. Many do not--I believe this to be unethical.

In civil court, both the plaintiff and the defense attorneys are bound to put forth the strongest case for their client and have NO obligation to present contradictory evidence--in fact, to do otherwise is unethical.

But politics is a merger of these two. While actually advocating for very particular positions, politicians like to posture that they are being scientific. They ALL quote some science to support them, whether it's Al Gore on the environment, or George Bush on global warming. The positions are different, the tactics are the same. Both claim the truth. Each of us must decide whom we think is being more truthful. We are stuck with it.

This happens all the time in the politics of our towns, our states, and our nation. Everybody must make the choice, every time they vote: Do I compromise, vote for the lesser of two evils, or if I'm lucky, vote for someone/something that approximately will follow some policies I approve of? Or do I "stand on principle" and basically throw my vote away? What do YOU do? (that's rhetorical, not for answering).

I can tell you that I have thrown my vote away, only to see the WORSE of two evils come to power and really make a mess.

Say there are two parties, the Clap-Trap party and the Hum-Drum party. Say you are generally sympathetic to the Hum-Drum positions, but they nominate a candidate that you really don't like. Meanwhile the Clap-Traps have nominated a candidate you detest. You can hold your nose and try to get the Hum-Drum elected to keep the Clap-Trap out, or you can toss your vote away and let the Clap-Trap come in and REALLY make a mess. This is NOT a reference to either actual party or the current situation--it can be any town, state or national election over the last 200 years.

Do I LIKE the fact that liars win elections more often than truth tellers--at EVERY level? No. Why should I? But after 51 years on this earth I have come to see that the best person for the job has NOTHING to do with how he/she is perceived by the voters.

One of the reasons my wife and I decided NEVER to live in a home-owners' association home ever again was in our one experience, we watched people lie like dogs on a rug to get into officerships, solely for their own personal benefit. They touted experience, legal knowledge, etc. but once in office many were willing to damage the community's interest solely for their own personal benefit.

So: Am I willing to trash the entire environmentalist movement because they are willing to tolerate crackpots who think chlorine is some plot to poison them? (shades of the mad general in Dr. Strangelove) Will we be better off if we do so? That is the question we each need to ask.

Carl.

[chem geek]

Ben and Carl,

Since some of the Disinfection By-Products (DBPs), including Trihalomehtanes (THMs), are known to be a problem with long-term exposure at levels of 0.08 ppm, the issue is not whether chlorine disinfection poses risk, but rather whether the risk is low relative to the risk of infection (Ben's point in earlier posts).

The rate of reaction for any chemical process is dependent on the concentration of each of the reactants as well as on temperature (and if catalysts are present, etc.). In a CYA pool, the concentration of the chlorine (HOCl and OCl-) that reacts with organics to produce DBPs is exceptionally low, typically around 0.1 ppm for HOCl and OCl- combined, so the rate of production of DBPs will be very low as well. In a non-CYA pool, as found in indoor pools, the level of chlorine (all of which is in the form of HOCl and OCl-) is usually at least 2 ppm, or 20 times higher. This higher level of chlorine is closer to the chlorine disinfection rates used in water treatment where the concern of DBPs (and the switch to using chloramines) has taken place (and remember that the concerns were with drinking the water, not just bathing in it). With the same organic loads, this means that the rate of production of DBPs will be 20 times higher. Spas have a higher temperature so 104 degrees vs. 80 degrees might have a higher rate of DBP production of 1.5x-4x (I couldn't find the rate constants and their temperature dependence for DBP production, but generally 10 degree Celsius higher temperature increases the rate by the range I indicated).

Ben had noted that asthmatics genearlly have problems only with indoor pools. I suspect that the lack of CYA use in indoor pools is at least part of the problem. Poor air circulation and the lack of sunlight which might breakdown the DBPs are other factors. This is part of the reason why I believe a small amount of CYA should be used for indoor pools though this would pose problems for easily shocking the pool (non-chlorine shock would probably need to be used).

My own personal experience (actually that of my wife's) is that the rubber in swimsuits breaks down rapidly (over one winter) when used in an indoor pool that I presume is not using CYA while there is no noticeable breakdown when used in our outdoor pool with CYA over the summer. Though rubber is not a typical organic from living things, it still gives credence to the principles outlined above. One of these days, I'm going to take my test kit down to the indoor pool my wife uses in the winter and will see what's really in that pool!

Richard (aka "chem geek")

[CarlD]

Richard:
the question that leaps to mind is what are the levels of CYA and FC that you are referring to and does this ".1" change as either or both CYA and FC change?

[CarlD]

Ben,
I have read your last post several times, and gave a reply that one time seemed to address it.

Now as I look again I see that you seem to be putting the context of the anti-chlorine people writing out there in the aether as being posters on your board.

The two forms of the argument need to be properly defined.

In running PoolForum you have set up a particular set of rules and standards that you expect members to adhere to. Fair enough--I don't pretend this is the public news media where all sides need to be presented.

Therefore I have NO objection to you preventing the anti-chlorine crowd from dumping their particular message here, nor do I object to your reasons--you see it as bad science and as dishonest propaganda. I don't disagree.

One of the reasons I have agreed to participate as a moderator is that, like you, I am tired of people being fed fairy tales (and EXPENSIVE ones too) about their pool care. I see PoolForum as a growing voice in the wilderness that, with demonstrable successes is showing how other techniques (for lack of a really good work for them) fail--consistently. I don't "believe" your techniques work--I don't have to take it on faith. I've observed them working repeatedly and predictably in my own pool and in the pools of others.

I don't feel you need to give "equal time" to people pushing the "slug" method of lowering T/A, to the electromagnets that show up, to the Nature2 type systems. When they show up with good science, I won't have to convince you to give them an airing--I know that you will simply review it and decide if the science is valid--no matter where it takes you. Till then, they go in the tinfoil hat cabinet or the Hall of Shame.

You're not bound to publish lies and liars.

But what happens when you are trying to change policy, and get involved with politics? You say you demand orthodoxy in your forum. Thankfully, I think that's not accurate. You always seem willing to investigate new ideas, and have them investigated, as long as there is a sound basis for doing that (not tin-foil hats here, please).

For example: When I first visited the PoolForum years ago, you were very skeptical about Intex donut pools--discounting the value and validity of them. You were fairly leery of A/G pools in general, though you have a section on them in PoolSolutions as well. And, of course, I had one of the early Intex EasySets. Still do, if the mice haven't eaten through it, buried somewhere in the shed. I argued: Wait a second, it's a real pool with real water, a real filter, you get just as wet--and the chemistry needs to be addressed. In fact, my favorite image is lying in a floating armchair, with a drink, on a lazy afternoon, listening to the ball game--and that it makes no difference if it's a donut or an inground.

Over the years I've seen you soften--even put forth the idea that AG pools get used MORE because people won't tolerate them in their yards if they are not using them--they'll get torn down faster than an IG will be abandoned.

Another example: DE in sand filters. Al and I have both been delighted with the results and have suggested other people try it, frequently. It's not orthodoxy, but it's logical. And you haven't said "No more discussion of DE in sand filters."

I could cite other examples, I can think of several--but all of them have something in common: they all had a logical basis and you "succumbed" to logic. To me, that's not orthodoxy. Unless, of course, your orthodoxy is facts and logic and truth, wherever it takes you.

But the other side is the side of politics and policy--the art of compromise. Sometimes you just have to hold your nose. Not here, not on the board, but out there when we go into our polling booths and form our coalitions to get something or other done. The "fellow travellers" in ANY political movement always have an unpleasant amount of mishegoss. A political movement is ANY organizing to influence the government--whether by convincing law makers to change laws, or electing law makers. There's always going to be people with that mishegoss.

I'm a motorcyclist, been one a lot longer than I've been a pool owner. There's ALWAYS someone posturing to limit or outlaw our activity. Frequently, it's in a way that's only good for one thing--drumming up votes. Even more frequently, they are citing BS put forth by the insurance industry (Bikes are very inconvenient to to them ) Sometimes, a lot of the OTHER positions of that person are ones that I agree with. I may HATE their position on bikes, but on other things that are far more important, the other candidate is worse. What do I do? Do I become a single issue voter, or do I do a cost-benefit analysis?

Then, of course, comes the great betrayal when the person gets elected and does the OPPOSITE of what they promised.:mad:

[chem geek]

Carl,

To keep my message short, I didn't give all of the details. With the following conditions:

pH: 7.5
FC: 3.0
CYA: 30
The following don't have a much smaller effect on HOCl:
Temp: 80ºF
TDS: 550
The following has no effect on HOCl:
CH: 300

You get 0.045 ppm HOCl and 0.048 ppm OCl for a total of 0.093 or about 0.1 ppm total for HOCl and OCl-.

I have been in communication with Ben on the detailed spreadsheet I created and plan to start a thread in the China Shop (perhaps this weekend) to start the discussion on getting real-world experiences from people. Though I am confident of the chemistry determining HOCl levels at various levels of CYA and FC and am also fairly confident of the 0.011 ppm HOCl level that is the minimum for disinfection (of easy bugs, not hard-to-kill ones), I am not at all sure what the proper levels of chlorine are needed to prevent algae nor to properly shock algae (and will likely vary by type of algae). This is where some real-world experience could help determine these values.

The spreadsheet is complicated and solves the chlorinated cyanurate equations iteratively since an exact solution requires solving a quartic equation (or ignoring a very minor species, a cubic equation) and even then you need to iterate to solve for the ionic strength influences on activity. Nevertheless, there is an approximate formula you can use so long as your CYA ppm is at least 5 times your FC (the formula really falls apart terribly below a ratio of CYA/FC of 3).

(ppm HOCl) = (ppm FC) / ( 2.7*(ppm CYA) - 6.6*(ppm FC) + 5.2 )

and if you are interested in the FC for a given HOCl (to construct the equivalent of Ben's table, for example), you can use the following which just solves for ppm FC from the above.

(ppm FC) = ( 2.7*(ppm CYA) + 5.2 ) / ( 6.6 + 1/(ppm HOCl) )

The constants in the above formulas are for a pH of 7.5 (which is the only parameter that significantly affects these constants). With the spreadsheet I can easily calculate the constants for other pH, but remember that the above formulas are approximate. For example, with FC of 3 and CYA of 15 the formula gives HOCl as 0.117 when the correct answer is 0.107. That's not bad (about a 10% error). However, with FC of 5 and CYA of 15 the formula gives HOCl as 0.400 while the correct answer is 0.246 (about a 60% error) which isn't very good.

Richard

[VOLDADDY]

Wow, the above post might as well have been written in Chinese to me, and I suspect 90% of the others here. We really appreciate all of the work people like Ben, Carl, Richard, Al, Janet, Michael and the bleach calc, et al...put in to this board, and breaking it down to laymans terms for everyone else to understand. Now I see why I didn't take chemistry in college, Biology and the 3 hour lab was enough for me. Kudos from everyone for all the work you guys and gals do. Too bad we all don't live near each other, or we could have a huge cook out and grill up some steaks to show our appreciation! (medium rare, of course ;))

[waterbear]

Waterbear, this winter ask me for some of the bromine literature I have.

I, for one, am not convinced that bromine has any real value for either pools or spas. And, I'm almost convinced that the use of BCDMH or any other source of bromine bound to dimethyl hydantoin should be strongly discouraged.
Ben, on this I agree with you 100%. I have never understood the need for bromine tablets in a floater since they are not effective unless the bromine bank is first established with sodium bromine and converted to hypobromous acid with an oxidizer such as chlorine. My feeling is that they are totally unnecessary since bromine sanitation can be carried out with only the sodium bromide and oxidizer.
I very strongly suspect that bromine has gained its positive reputation purely based on the absence of information. My impression is that chlorine and its compounds are far better known and understood than are bromine and its compounds. It's also my impression that bromates, which form under many conditions if bromine is used in pools or appears in source water, is considered a more serious 'bad actor' than are many of the chlorine products.
I have read some vague things alone these lines but have not been able to find out very much info at all.
Regarding bromamines, I've never been able to find *any* information on what sort of bromamines appear in pools and spas, nor have I ever found a study that substantiates the oft-repeated pool industry maxim that "bromamines, unlike chloramines are good sanitizers".
Neither have I.
It's worth noting, that with the demise of Hydrotech (purchased by BioLab), and the death of Jock Hamilton (founder of United Chemicals), pro-bromine pool industry press seems to have diminished to a bare trickle. It makes me wonder if ANYONE, except those trying to sell it, ever thought it was a good idea.

Color me skeptical!
Bromine's often quoted advantage is that it is active over a wider pH range (up to 8.0) and is more stable at higher temperatures but I have not been able to find any actual info to support this. Also bromine is a known sensitizer and reactions to bromine santized pools and spas is not uncommen. It is intersting that what I have read (in a CPO training manual) on the other halogens and why they are not applicable to pool sanitation are that flourine is too expensive although it would be extremely effective (although I personally believe it would also be very toxic) and that iodine in concentrations high enough to sanitize would color the water and would still need chorine present as an oxidizer. I have not been able to find any info to either prove or refute these statements. It makes me wonder where the 'experts' get this information from!
Ben

Color me skeptical too!

[DavidD]

pH: 7.5
FC: 3.0
CYA: 30
The following don't have a much smaller effect on HOCl:
Temp: 80ºF
TDS: 550
The following has no effect on HOCl:
CH: 300

Richard,

What effect, though small, does TDS have on HOCl? Would the fact that salt makes up the majority of TDS in a particular sample increase the negative effect? Go easy on my limited abilty to grasp basic chemistry .:)

Dave

[chem geek]

Richard,

What effect, though small, does TDS have on HOCl? Would the fact that salt makes up the majority of TDS in a particular sample increase the negative effect? Go easy on my limited abilty to grasp basic chemistry .:)

Dave
In the presence of even small amounts of Cyanuric Acid (CYA), TDS has almost no effect on HOCl. So the calculations for a salt (SWG) pool would be the same as for a regular non-salt pool.

In a pool with no CYA, then the HOCl concentration from a non-salt pool to a salt (SWG) pool is lowered by around 5.7% (independent of Total Free Chlorine (FC) level).

Stop reading at this point.:) The following is for those who might want a more technical explanation.

(The technical reason for the difference is that without CYA, the TDS affects something called "ionic strength" that affects the equilibrium between the neutral HOCl and the charged OCl-. With CYA, the concentration of HOCl is instead determined by the CYA-like equilibrium that has charged species on both sides of the equation so the ionic strength effect is cancelled out. :eek: )

[fcfrey]

So ---- What have we learned??

After nearly two months, 90438 Characters (with spaces), making up 15683 Words, in 45 posts from 12 different contributors including our Administrator and Moderators, we have had a very spirited debate.:D We went over, under, around and some, directly to the question, which in case we have forgotten, “Is it safe to swim with an elevated chlorine level?”

1. We have explored the politics, the fears, the fear mongers in the “Greenie” gang, and the chemistry behind effective chlorination.

2. We’ve also discussed the way our mainstream media runs off with half of the story and creates the rest itself, true or not, to “sell papers”. Ben has very accurately pointed out the fact that “the fears that people bring to the Pool Forum are not, for the most part, irrational fears. Rather they are a rational response to the persistent and hyped anti-chlorine hysteria shrieked out by modern environmentalists and uncritically parroted by the mass media”. The latter being one of the most profound statements of the entire thread.

3. We have learned that there are many forms of disinfection available for our pools including sunlight, UV, peroxide, bromine etc. etc., but none do the job as effectively as chlorine.

4. We have learned that the real dangers are from the disinfection by products (DBPs) and Tri-Halo-Methanes (THM) particularly in indoor pool environments, but these problems really do not apply to our outdoor residential pools where there is plenty of ventilation. In addition the fear of chlorine being directly absorbed through the skin has been largely debunked, but there is evidence that some halogenated compounds -- that may, or may not be present in pools -- can be so absorbed. We should, however, keep in mind that these compounds are found in pools in many forms including salt and the very liners that keep the water where it belongs (in the pool).

5. We’ve discussed lighting and algae formation in aquariums and the relationships to disinfection and sanitation.

6. We even discussed DDT.

7. We have learned that there are some members of this forum that are overly sensitive to what other members quote and are willing to lash out with concealed retribution, leaving the recipients with their “feel bad” hurt.

8. We have learned that there is a need for compassion for the “unlearned” and those skeptical of the principles and practices taught here.

9. And finally, we have gone --- w-a—y off topic to explore the area under CarlD’s bed:eek:

But what about the question-----------------?????

I think it is safe to say, “that all depends”. It depends on who is doing the tests, and are they accurate. It depends on how high your cyanuric acid level is. It depends on the level of your chloramines (combined chlorine). It depends on every other chemical we put into the pool. It depends on the environment in which your pool exists. But it really depends on how comfortable you are with what the administrators, moderators and other contributors on this forum believe.

For me --- nearly two months after posting the question, and reading another 1000 or more posts on a lot of related subjects, I will now swim in my pool whenever it is 10 ppm free chlorine or less.:) I’m comfortable with that decision, a decision that I probably would not have been able to make without the debate that my question has brought forth.

I’ve added another 656 words to this thread so I need to bring it to a close.

Lastly --- I feel compelled to thank Ben, for providing this forum. Richard, for his detailed chemical explanations and charts. The Moderators who keep things going forward with their great advise. And finally all the newbies, some of whom ask some of the most ridiculous questions:D (sometimes they make me laugh) which bring out the very best information money could never buy.

Frank