Does local Govt participate in spreading the stabilized chlorine deceit?

[Water_man]

The members and readers of this forum know that habitual use of “stabilized chlorine” products such as dichlor and trichlor is bad for your pool and the problems it generates cause a vicious cycle of acquiring more and more products needed to deal with problems that could and should have been eliminated had the pool owner/operator not used stabilized chlorine products.

We’ve also learned and realized that dealers, shop owners and manufacturers haven’t done anything in order to educate the public because they would sell less products had the simple truth be known.

I was curious to find out what do public and local government authorities and offices know and recommend regarding proper use of chlorine and stabilized chlorine products. I conducted a small search which was by no means comprehensive and conclusive, but it gave me a hint of what’s going on out there. I was shocked and appalled at what I found.


Here are two “fact sheets” by two Health Departments. They both use the same document, except for minor changes. This is the

Pennsylvania Dept of Health paper.

This is the

Lincoln, NE Dept of Health Paper.


Here’s a summary of what they tell and recommend. Most of what they tell corresponds to what we know, although they are wrong about a few details (see below). However, based on the knowledge that they present, their own recommendations should have been radically different!


The facts, as they present them:

1. CYA level of 20-50 ppm is essential for outdoor pools in order to protect FC from UV degradation.

2. Stabilized chlorine products such as dichlor and trichlor are commonly used products which supply both FC and CYA.

3. When CYA levels are higher than 80 ppm the downside of CYA overrides its benefit and chlorine is less and less effective.

4. They recommend a 2 ppm FC level for proper sanitation. Here they lack the knowledge that FC level should be a function of CYA level. But ignorance is not a crime.


So what do they recommend, based on the “facts” that they present?

Stabilized chlorine products:
“Both dichlor and trichlor release cyanuric acid to the pool water. It is not necessary to put additional cyanuric acid into a pool that uses dichlor or trichlor.”

What to do when CYA is high?
"Cyanuric acid should be tested at least once a week to keep concentrations below 30 ppm.
Cyanuric acid levels should never exceed 100 ppm.
Partially drain pool and add water to reduce cyanuric acid concentration."


What about the only reasonable conclusion and recommendation that they should have come up with, namely:
“Because stabilized chlorine products continuously increase the level of CYA in the water, it is recommended NOT to use them!”

Nada! It doesn’t exist. Drain the pool and waste water!


What would you think about a Health Dept that would come up with such a “fact sheet” about cigarette smoking:

“1. Cigarette smoking is bad for your health.

2. It has been established beyond doubt that the chance of a person who smokes 5 cigarettes a day to get cancer or cardiovascular diseases is k% higher than that of a non smoker; l% for a 10 cigs a day smoker, m% for a pack a day smoker, n% for 2 packs a day smoker, and o% for 3packs/day smoker, and o>n>m>l>k, and even k and l are significantly high.

3. Therefore we recommend that one should not smoke more than two packs a day.”


Wouldn’t that be outrageously ridiculous?

Isn’t AVOIDING recommending AGAINST the use of di and tri-chlor is as outrageously ridiculous?

Is the reason for this avoidance the result of sheer stupidity or is it a conscious participation in spreading the deceit?

You be the judge.

[CarlD]

Incompetence and believing fairy tales isn't limited to local governments. Read Ben's articles on PoolSolutions.com to get a full view of the irrationality of the chlorine recommendations...they don't realize that level of chlorine in drinking water that they consider to be safe is HIGHER than the levels they consider to be safe in swimming pools.

I suspect it's mostly due to being poorly funded, not a very "sexy" topic, and being fed info by the chem companies who want it to stay that way.

[chem geek]

I agree with Carl. I don't think this is any sort of conspiracy, but rather just poor education. The position that you are taking that CYA should not be used at all is just as extreme as a position that its level doesn't matter up to 100 ppm. CYA does have a beneficial purpose, but that purpose has been obscured by an industry that believes that full disclosure would reduce stabilized chlorine sales. So the problem is not that CYA is used at all, but rather that it is used improperly (i.e. not at an appropriate level and not with an understanding of the FC/CYA ratio roughly determining chlorine effectiveness).

Both the health departments and the industry correctly say that CYA protects chlorine from degradation from the UV rays of sunlight. Without any CYA in the water, half of the Free Chlorine (FC) would degrade every half hour in direct noontime sun. So some amount of CYA is needed to protect chlorine from such rapid breakdown.

The fact that is missing is that the reduced killing power of chlorine isn't just something like a 30% reduction or a factor of 2 or even 5 but rather a factor of 20 to 100 depending on the FC/CYA ratio. At an FC of 3.5 ppm and CYA of 30 ppm, 97% of the chlorine is bound to CYA and only 1.5% is hypochlorous acid (the other 1.5% is hypochlorite ion). Though that sounds bad, it really isn't because the other fact that isn't described is that it takes an incredibly small amount of chlorine to kill most pathogens. I wrote about this more in this thread.

So the right way to look at this is that you really only need an FC level (at a pH of 7.5) of around 0.002 ppm to kill most bacteria faster than they can reproduce -- that is, to prevent runaway growth. It takes a higher level of around 0.06 ppm or so to inhibit green algae growth (up to very high phosphate levels of perhaps around 3000-4000 ppb). To prevent person-to-person transmission of disease, the algae inhibition level of chlorine would be more appropriate for faster bacterial kill times such that 99% reductions in bacterial population would occur in a minute or two.

The problem is that one cannot maintain such low levels of FC since the absolute chlorine demand would quickly consume such small quantities. So some sort of chlorine buffer is required to provide a chlorine reserve while at the same time reducing its instantaneous effectiveness. If one does not use CYA at all, then the 1-2 ppm FC levels needed to not run out locally and to be more readily maintained would be at a much more powerful level of chlorine than is needed by a factor of 10-20 or more. This results in faster oxidation of swimsuits, skin and hair as well as faster creation of disinfection by-products and in some cases greater end quantities of such products. This is the typical situation found in most indoor pools because CYA is not used because only the sunlight protection effect of CYA is thought about and not its chlorine buffering effect.

Richard

[Water_man]

The position that you are taking that CYA should not be used at all is just as extreme as a position that its level doesn't matter up to 100 ppm. Richard

I'm not saying that CYA shouldn't be used. I'm saying what has been advocated on this forum : that a habitual use of di and tri-chlor products for ongoing sanitation shouldn't be used at all for reasons we all know. This should be the most reasonable conclusion from the facts presented by these Health Dept officials, but yet they accept them as commonly used products without warning against their use. I don't believe they avoid coming up with the most reasonable recommendation because of poor education. And they can't be that dumb either.

[chem geek]

Sorry I misinterpreted what you wrote.

I've been working with several of them (environmental health directors) and they aren't dumb (in fact, they are quite intelligent), but most are misinformed based on traditional industry statements. Some have seen things like ORP levels that seem to track FC/CYA ratios and some have come across this Pool Water Chemistry thread and communicated with me. I really don't think they are doing any intentional withholding of information. For their commercial/public pool environments, they do set limits on CYA levels and enforce regular testing so in practice this does limit the amount of stabilized chlorine that gets used -- many of these large facilities use chlorine gas or large SWG systems. The ones that do use stabilized chlorine do regular water replacement to keep not only CYA lower but to remove general organic contaminants and salt.

It really isn't the place of the public health departments to put out rules of thumb for the residential market. They do note that continued use of stabilized chlorine products can lead to a buildup of CYA. They just never calculated the specific quantities that really show how quickly the buildup can occur (i.e. every 1 ppm FC from Trichlor adds 0.6 ppm to CYA, etc.).

I think that for the residential market, the place that education needs to get fixed are the training courses such as CPO from NSPF and TECH from APSP. I've written to these organizations and continue to push this issue though nothing definitive has happened yet, but I'm a bulldog when it comes to things like this and I won't give up. Also, the education of pool stores, especially large chains like Leslie's, needs to be improved.

Another area that needs to be addressed is how to handle the protozoan cysts. The current Fecal Accident Response for Pool Staff from the CDC indirectly bans CYA entirely since there is no practical way to kill Crypto using chlorine after a diarrhea accident. Actually, with lower CYA levels it is possible, though difficult, since one just needs to raise the FC to approximately 10 ppm FC higher than the CYA level and that results in roughly the equivalent of 10 ppm FC with no CYA. I've been floating the idea around of using chlorine dioxide generated by adding sodium chlorite to a stabilized chlorine pool. I got the idea when I was in REI and saw some water purification tablets that contained sodium chlorite with Dichlor. Chlorine dioxide is at least 10 times more effective than chlorine against protozoan cysts so a level of a few ppm overnight should be all that is needed (and it needs to be overnight since chlorine dioxide breaks down in sunlight). As for ongoing sanitation that can kill Crypto, it looks like UV might be the best bet, though is still limited by the time it takes to do turnovers of water in the pool (it takes 4.6 turnovers to get 99% of the water exposed to the UV, assuming ideal circulation).

Richard


Attached from:
http://www.cdc.gov/healthywater/pdf/...mendations.pdf

[CarlD]

I don't say either Di-chlor or Tri-chlor shouldn't be used. I say they shouldn't be used when CYA reaches a certain level or when pH drops to a certain level.

Tri-chlor is great stuff for a new concrete pool that's curing. It can be good for leaving your pool while on vacation.

But, (and here's the "but") you need to test weekly for CYA, TA, FC, CC etc and daily for Chlorine and pH. So you watch them and when they hit the limits change what you are doing.

But you should be doing that anyway, regardless. That's just good pool maintenance (see my sig line)

[Poolsean]

I for one, disagree with water man's post, and maybe I'm misunderstanding your post. Your quote seem to imply that the only conclusion is to not use cya.

"What about the only reasonable conclusion and recommendation that they should have come up with, namely:

“Because stabilized chlorine products continuously increase the level of CYA in the water, it is recommended NOT to use them!”
Nada! It doesn’t exist. Drain the pool and waste water!"

Most health departments deal with guidelines that have been industry standards for years. This is not to say that they are correct or incorrect, but that, as Chemgeek said, there are some misunderstandings of the chemicals they are testing for. I've been dealing with health officials for YEARS on the salt chlorine generator side.

CYA has always been an issue of conflict.
Outdoor pools need Cya. The two links you attached, are in Lincoln Nebraska and Pennsylvania, both of which winterize pools, and naturally drain down water every year. So, there's a natural dilution of any accumulated cya.

I DO agree with everyone that TOO much cya is not good. I do know that with Salt Chlorine Generators, 80 ppm of cya has proven to be more effective than 50 ppm. CAT controllers, manufacturer of ORP/pH controllers, recommend no more than 50 ppm.

[Water_man]

I for one, disagree with water man's post, and maybe I'm misunderstanding your post. Your quote seem to imply that the only conclusion is to not use cya.

"What about the only reasonable conclusion and recommendation that they should have come up with, namely:

“Because stabilized chlorine products continuously increase the level of CYA in the water, it is recommended NOT to use them!”
.

Sorry, you misunderstood. "NOT to use them" referred to "stabilized chlorine products", namely dichlor and trichlor, because of the obvious reason : a continuous use of these products increases the level of CYA continuously.

[CarlD]

Sorry, you misunderstood. "NOT to use them" referred to "stabilized chlorine products", namely dichlor and trichlor, because of the obvious reason : a continuous use of these products increases the level of CYA continuously.

But that is negated by proper, regular testing and by adjusting your chlorination method appropriately.

Seriously, the only WRONG way to chlorinate is without testing or compensating when the test results tell you to.

(....OK, ok, and mixing chlorine types in the same container, like the skimmer or automatic chlorinator--but that's just plain dangerous and stupid... )

[chem geek]

Also, though not recommended on this forum (due to extra cost, more than anything else), there are other ways of dealing with higher CYA levels. One can use a weekly maintenance dose of PolyQuat 60 to be able to have somewhat lower FC levels at higher CYA levels. One could spend even more for a phosphate remover and have even lower FC levels with even higher CYA levels and not get algae. One could use a copper-based algaecide and prevent algae while simultaneously staining your plaster pool if the pH rises (or you use excess copper).

I generally don't like all or nothing rules when there are alternatives. As Carl says, if you measure your pool's water chemistry regularly, then you can stay on top of the CYA level. Also, in smaller pools with weekly backwashed sand filters and short swim seasons, the CYA level can be kept more in check such that even Trichlor could be used as a primary source of chlorine. It's all about knowledge and adjusting one's routine based on that knowledge.

Richard