Safe swimming with elevated chlorine

[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.

[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 )

[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. )