Does local Govt participate in spreading the stabilized chlorine deceit?

[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

[Water_man]

As Carl says, if you measure your pool's water chemistry regularly, then you can stay on top of the CYA level.
Richard

You can measure your CYA to your heart's (and Taylor's) delight day in and day out, but if you keep using trichlor and there's no significant fresh water exchange in your pool, your CYA will keep rising up to a critical point. Ain't I singing to a choir here?

[Water_man]

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.

But this is NOT what this clowns of the Health Depts are saying! They are saying : "use trichlor , as the most common chlorination product, which supplies both active chlorine and CYA, but be careful! When your CYA reaches 80 or more you're in trouble! Drain the pool!"

They should say: "Use trichlor only when you have a new pool, and once your CYA reaches 50 STOP USING IT!"
This should be the only logical recommendation regarding the use of trichlor products.

In both cases, the ongoing testing of CYA is a given.