Are 70-80 CYA Levels for SWG Pools Safe?

sagosto

Well-known member
May 28, 2019
58
Mahwah, NJ
I am taking a beating on the home front regarding the 70-80 CYA level range for SWG pools. It is true there are a ton of documentation regarding 30-50 CYA range including CDC and WHO (https://www.who.int/water_sanitation_health/bathing/srwe2full.pdf). I am still a bit unclear why 30-50 seems to be ideal for non-SWG and 70-80 for SWG. I am not sure how to handle this at this point because the wife is demanding 30-50 range due to the WHO language regarding heath concerns due to ingesting water with high CYA levels.
 

ajw22

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Jul 21, 2013
7,803
Northern NJ
The science is explained in

 

duraleigh

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Too many chiefs and not enough indians. One of you has to manage the pool. It is pointless to co-manage when you do not agree and she apparently doesn't use TFP.
 

Donldson

TFP Expert
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In The Industry
Jun 12, 2009
3,819
NW Ohio
You can run an SWG and lower CYA levels, if that will save a marriage then do it. 😉

The higher CYA levels better protect the chlorine generated by the SWG. Less chlorine burn off to the sun means less chlorine required of the SWG. Less chlorine production means longer cell life. That's really all it is, if the SWG can keep up with the higher UV losses then it is just as safe.

Regarding the misconceptions here, CYA buffers chlorine at a set amount. If you look at the SLAM levels they are all the same, 40% FC to CYA. And they all provide the exact same active chlorine level, which is less than a pool with zero CYA and 3 ppm FC. You might recognize that example as a pool that is within CDC/WHO guidelines, yet would be far more harsh on people, swimwear, and pool/equipment.

Government agencies don't recognize the effects CYA has in the water. Yet. There has been recent movement, but change is long in this industry. Follow what you wish, but just know that when it comes to this we have the science backing us. Did the WHO provide you with the science to back up their recommendations? Or are they just being taken at their word because of their name? I don't expect an answer, just something to think about.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
7,803
Northern NJ
Yes but CDC/WHO are not aligned with this chemistry in their literature.
CDC/WHO has no reason to change their position on it. I doubt they have done any research on the area. You can use whichever guidelines work for your household.
 

sagosto

Well-known member
May 28, 2019
58
Mahwah, NJ
Too many chiefs and not enough indians. One of you has to manage the pool. It is pointless to co-manage when you do not agree and she apparently doesn't use TFP.
To be honest, she is extremely intelligent and I say that conservatively. I say this in confidence of course. :) But, if you consider the literature from major sources, they simply trump this forum from an outsider's perspective. Simply put, there's a lot of conflicting info so it is hard to take a chance when major groups such as WHO/CDC say it's a health issue.

You can run an SWG and lower CYA levels, if that will save a marriage then do it. 😉

The higher CYA levels better protect the chlorine generated by the SWG. Less chlorine burn off to the sun means less chlorine required of the SWG. Less chlorine production means longer cell life. That's really all it is, if the SWG can keep up with the higher UV losses then it is just as safe.

Regarding the misconceptions here, CYA buffers chlorine at a set amount. If you look at the SLAM levels they are all the same, 40% FC to CYA. And they all provide the exact same active chlorine level, which is less than a pool with zero CYA and 3 ppm FC. You might recognize that example as a pool that is within CDC/WHO guidelines, yet would be far more harsh on people, swimwear, and pool/equipment.

Government agencies don't recognize the effects CYA has in the water. Yet. There has been recent movement, but change is long in this industry. Follow what you wish, but just know that when it comes to this we have the science backing us. Did the WHO provide you with the science to back up their recommendations? Or are they just being taken at their word because of their name? I don't expect an answer, just something to think about.
It makes sense but if there is a health issue due to ingestion at the higher level, I'd rather not take that risk. While Internet is great, it is filled with bad and even stale information. I try to see both sides and come to my own conclusion whenever possible.

How do you define active chlorine? I realizeFC, CC, and TC.
 

Dave31410

Bronze Supporter
Feb 27, 2018
109
Savannah, GA
quote from the report; "Levels of cyanuric acid should be kept between 50 and 100 mg/l in order not to interfere with the release of free chlorine, and it is recommended that levels should not exceed 100 mg/l "

Sounds like just what this forum recommends
 

mickey4paws

Bronze Supporter
LifeTime Supporter
Apr 10, 2009
650
S.E. MI
When we got our SWG 10 years ago, I read the manual from the manufacturer. The range that is recommended for CYA is 70-80 so that's what we've been following. Why would manufacturers makes these recommendations if the WHO says they're dangerous? It doesn't seem likely that they'd want the liability. Anyway, I went to the WHO article (146 pages from 2006). I'm at work so only skimmed a few sections but mentioned not going higher than 100 CYA.
 
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ajw22

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TFP Guide
Jul 21, 2013
7,803
Northern NJ

So CDC says 15 which is unmeasureable with consumer tests. Your wife says no higher than 50. And TFP recommends SWG in the 60-80 range.

Since testing accuracy for CYA is +/- 10 ppm anyway. And in NJ CYA 50 will work just fine with a SWG. Those folks in the Southwest really need to CYA 70.

I really don't think you have much to argue about here. Unless you just like questioning stuff.
 

ajw22

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TFP Guide
Jul 21, 2013
7,803
Northern NJ
I think I have legit questions. I'm going to stick with 40-50.

The science for TFP recommendations are posted here. Let the others support the science for their recommendations.

CYA 40-50 will work fine for you. My CYA in NJ is 60.
 

duraleigh

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Apr 1, 2007
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I have posted this before and it is applicable now. This is not a debate forum. It is, however, a teaching forum that has proven successful for thousands upon thousands of pool owners. It is based on science and has been proven accurate and effective time after time after time.

Sagosto, you are absolutely free to care for your pool as you and your wife think is best......that's what I do as well. This is just not the place to argue your position.
 
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woodyp

Mod Squad
TFP Expert
LifeTime Supporter
Apr 17, 2010
10,546
East Texas
sagosto:
"It makes sense but if there is a health issue due to ingestion at the higher level, I'd rather not take that risk."

How much pool water were you thinking about drinking? There are a lot better reasons not to use pool water for potable water other than CYA levels. The question is moot.
 

sagosto

Well-known member
May 28, 2019
58
Mahwah, NJ
And this is why forums get a bad rap because members become defensive. I have two little kids who will/have drink pool water either by mistake or they think it is funny. I am not lugging water in the house for ice tea. That comment is ignorant.

Second, I am on the side of this forum but trying to see both sides to draw my own conclusion. No arguing but what should be a healthy discussion. There is no value if one can or speak freely without these sort of responses.
 
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JamesW

TFP Expert
Mar 2, 2011
15,509
In my opinion, 30 to 50 is perfectly fine to use.

If you feel better about that range, that's what you should use. The main thing that we teach is the ratio of fc to cya.

As long as you maintain the ratio according to the fc/cya chart, you should good.

We have found that using a higher cya can be beneficial but I wouldn't have any issues with 40 to 50 cya.
 
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