Will the Industry Ever Change CYA/FC Parameters?

Flying Tivo

Well-known member
Jan 24, 2017
1,991
Monterrey, NL, Mexico
If you think you guys have it bad, in MX they are selling products with blue coloring so the pool will look better and it contains citric acid and we all know what that does to FC. Its very hard to combat ignorance face to face. We need a strategy like FAKE NEWS, small stories all over the country until they merge in onto a big one and think its true.
 
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jseyfert3

Silver Supporter
Bronze Supporter
TFP Guide
Oct 20, 2017
1,467
Southern WI
Pool Size
15000
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Chlorine
Liquid Chlorine
However, while liquid is available at two places: Walmart and Ollies Bargain Warehouse in this micropolitan area of around 150,000 people; those two stores don't move much product off the shelves from what I can tell, although this year it has been somewhat more making me think that some owners and pros in the area had previously been using regular bleach. Regular bleach this year has sort of dwindled in the size of the containers and the amount of stock on the shelves at 1.5% stronger concentration in my area, and so it really can't be used as a regular source of chlorine easily. To use liquid chlorine in my area, you've got to watch when the shipments come in and then also the restocks of it end early July making fresh-date liquid use hard to manage.
That's unfortunate. I've bought 12.5% liquid clorine for $3.99 from Menard's (which isn't in TN) since I got my pool up in mid-June, and once before that for our spa. It's never been older than two weeks, or in other words, it's getting used and replaced with new stuff. They also have 31% muriatic acid for $3.99 a gallon too. Between these two things, Menard's is my go-to for pool chemicals. The only pool and spa shop I've gone to (for spa filters and filter sand), about 20 minutes away because the closer one was rated terribly on Google Maps, doesn't have any liquid that I saw, and any pool stuff they did have was insanely expensive. Lots of "magic potions" and tablets though.

I haven't been doing this for long, our inflatable spa in previous years just used bleach, as a spa could nurse a bottle of 8% for a month or two, but with the pool at about 2 gallons of 12.5% a week bleach just isn't economical so I no longer buy it. I think what @Leebo says is correct, except I don't think it's being done at the high end, but at the low end. More that you take a store like Menard's, who unlike a pool store isn't going to stock anything that doesn't move quickly. They start selling liquid chlorine, and find it moves quick, so they sure as heck will make sure they stay stocked on liquid chlorine if it's a hot seller. If enough people stopped buying pucks, Menard's would drop them. Essentially, a large enough customer base (due to TFP) has stopped buying pucks and started buying liquid chlorine. Stores like Menard's start buying more liquid chlorine to match, and less pucks.

It sounds like Menard's knows what to sell, but the stores in your area haven't caught on yet.
 

Silver_2000

Gold Supporter
LifeTime Supporter
Nov 29, 2015
568
Carrollton tx
follow the $
Pool stores depend on the traffic the chemicals and testing generate
they make zero $ from people using SWG or Walmart chlorine
 

Katodude

Silver Supporter
Aug 22, 2017
1,273
West Palm Beach/Florida
Pool Size
15000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Hayward Aqua Rite (T-15)
:goodpost: This is exactly the disconnect and why I am very slow to offer advice to pool owners not seeking it. They say, " a pool service is cheaper and I don't have to think about it". It is like having a yard guy or a house cleaner they say. They refuse to see the subtle clues of a water imbalance and when they can no longer ignore problems they refuse to associate them with their flawed methodology and instead double down on more chemicals with fancy names. :suspect:

It gets worse. One of my buddies takes his water to the pool store once every two months for a test and then throws in whatever they tell him. Usually it is CYA. He just told me the other day they told him to CH to his pool, which he bought from them and did. We have fairly hard water down here (not as bad as the west coast guys) and there is no way his pool was low on CH. He has an auto fill and is constantly adding water and calcium with it. His only saving grace is he has a SWG so he manages to survive without too much trouble.
 

gregsfc

Bronze Supporter
May 27, 2014
204
Cookeville,TN
I've been digging a little into this public swimming pool regulation thing. Believe it or not, it's likely going the way of BBB/TFPC, but we'll know for sure at the end of the month. I just got an email back from the Council for the Model Aquatic Heath Code (CMAC); I know, that's a mouthful, but they basically advise the CDC on changing safety and health regulations for pools and such. TFP's own Chem Geek has headed a comittee that did a study in 2017 and concluded that fc and cya should be regulated together instead of separately and also concluded that cya/fc should be a minimum of 20. If you turn that around to the way we teach it; that's saying fc must be at least 5% of the cya level. But keep in mind, this would be the first time that a ratio between the two chemicals was ever proposed, let alone inacted. Their work got published in a scientific journal in 2019, and now it is before the change committee. They voted yesterday, but it's not public yet. I'll report back when it goes public. Supposed to be towards the end of August. Then there is a comment period; and then in Oct., it will be inacted. I looked up my state's current rules on chlorine and cya. It's .5-3 and 0-100 respectively, so a public pool in TN can have cya at 100 and fc at .5 and it's considered safe. This new rule would require fc at 5 with cya at 100 (ten times what it is now), but also may require the limit on cya down to 90. This would be a huge change for public pool regulations/advisement across the country. They also have to get the EPA to change the current limit on fc, which is currently a max of 4; not sure how that will work into it; bit change is coming thanks to our Chem Geek who proved all this to us a few yesrs ago right here!
 

gregsfc

Bronze Supporter
May 27, 2014
204
Cookeville,TN
I mis typed the organization acronym. It is CMAHC. If you go to their website, it's a dot org. They have the 2017 study on there. It's under Ad Hoc comittees; the one on "stabilizers". There is also a 2019 announcement where the CMAHC seems to be very supportive of the Ad Hoc committee's findings. Andlastly, if you do an internet search on "Richard Falk pool chemist", you can find and read where their study was published in a scientific journal in 2019.
 

gregsfc

Bronze Supporter
May 27, 2014
204
Cookeville,TN
Ther CMAHC voted Aug 3. The podcast and meeting notes are not yet public, so I don't know the outcome. The estimated publish date was told to me to be late August. It still has to pass through many bureaucratic steps before the cya/fc 20 gets published in the new MAHC published by the CDC, but the results of this vote is the one that really counts. I listened to one podcast; it was the last one. They voted on everything except for cya-related new codes. They saved cya for a session all by itelf. When they mention Richard in their meetings; they say his name like he's a pool water chemistry god; sort of like what we do here. That's all I know.
 

mgtfp

Bronze Supporter
Mar 5, 2020
780
Melbourne, Australia
Pool Size
66000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Astral VX 7T
Thanks for the update. Looks like they are saving the best for last...
 

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gregsfc

Bronze Supporter
May 27, 2014
204
Cookeville,TN
Okay so the TRC has three meeting date notes linked to the CMAC websites that have already occurred in August. I'm thoroughly confused on some of the votes and what they mean and how it will exactly change things.

It looks like that they compromised on the ratio. They all agreed with the cya/fc 20 standard as "right", but decided to go with only 30, as it would be a step in the right direction and not too invasive on industry. That would mean that at the maximum 90 ppm cya; fc could be as low as 3 instead of the committee's proposed 4. I was confused about another vote that had too much of a mix between yes and no votes and what that means. There was argument about letting cya be allowed up to 180, as opposed to 90, as long as the operator could measure and control and keep the ratio at 30. It was an overall abstain vote by the committee, because they were so split. So I guess that either reverts back to the previous vote on amother merting date or the previous MAHC, which I don't know the current guidance on max cya. So I don't know what that does or means. Also, it seems that they've voted to reduce the max FC allowed from 10 down to 5. I know that California is currently 10 in their health code. Tennessee, my state, is 3. I can seen how 10 could be dangerous for indoor pools, but I was confused by what that vote means for the model as it stands now, and I'm not sure if that California is even subject to the EPA. The current EPA limit is 4, so I don't know how that gets rectified.

Anyway, I think that to truly understand all of this, I'd have to listen to all three podcasts. There was lots of debate about everything that Richard's stabilizer ad hoc committee proposed. I can see why, it was substantive changes to large degree on actual limit regulations and new control concepts.

It seems overall, they were in agreement with everything from a necessary and scientific standpoint, but concerned with how great the changes were and how well they could be regulated aand managed in the industry.
 

red-beard

Gold Supporter
May 27, 2019
798
Houston, TX
Sounds like a typical political committee. "We all know that the proper ratio is 20:1 CYA to FC will make sure that bacteria are killed. But that is a big step, so let's do a ratio of 30:1". No one cares about the science.
 

red-beard

Gold Supporter
May 27, 2019
798
Houston, TX
Using Chemgeeks HOCl chart, at 100 CYA, 3 FC would be "safe" with bacteria, but that would need to be the lower limit. I think they want 4 FC to give some room for the FC to be different in different parts of the pool.

I think the 7.5 ratio works for us to insure that our stagnant areas in our residential pools do not become harmful or have algae. Most "commercial" pools, there is so much swimming, and the uniformity of the design, that there are not the same number of stagnant areas.
 

Rattus Suffocatus

Silver Supporter
Jun 5, 2019
1,300
Corona de Tucson, AZ
That's unfortunate. I've bought 12.5% liquid clorine for $3.99 from Menard's (which isn't in TN) since I got my pool up in mid-June, and once before that for our spa. It's never been older than two weeks, or in other words, it's getting used and replaced with new stuff. They also have 31% muriatic acid for $3.99 a gallon too. Between these two things, Menard's is my go-to for pool chemicals. The only pool and spa shop I've gone to (for spa filters and filter sand), about 20 minutes away because the closer one was rated terribly on Google Maps, doesn't have any liquid that I saw, and any pool stuff they did have was insanely expensive. Lots of "magic potions" and tablets though.

I haven't been doing this for long, our inflatable spa in previous years just used bleach, as a spa could nurse a bottle of 8% for a month or two, but with the pool at about 2 gallons of 12.5% a week bleach just isn't economical so I no longer buy it. I think what @Leebo says is correct, except I don't think it's being done at the high end, but at the low end. More that you take a store like Menard's, who unlike a pool store isn't going to stock anything that doesn't move quickly. They start selling liquid chlorine, and find it moves quick, so they sure as heck will make sure they stay stocked on liquid chlorine if it's a hot seller. If enough people stopped buying pucks, Menard's would drop them. Essentially, a large enough customer base (due to TFP) has stopped buying pucks and started buying liquid chlorine. Stores like Menard's start buying more liquid chlorine to match, and less pucks.

It sounds like Menard's knows what to sell, but the stores in your area haven't caught on yet.
I miss Menards. Midwesterners: Try for a month just completing your projects by going to Home Depot or Lowe's but not both-- and not Ace Hardware, and you will get what I mean. You mostly can do that with just Menards. I miss Aldi's too but there is hope if I stay here for that one, they are opening their first store in AZ two hours away. I have actually considered mail ordering stuff from Menards in some cases the cost plus shipping is less expensive... I am serious. Sad.

However the Midwest is different, especially with Muriatic Acid. It's use to do work there, etch concrete, clean up rust, etc. It's usually sold in onesies and it's cheap. Here it's marked "Pool" and sold as two bottles only (if you find one, it's $10) for $14-16 for the two bottles. The Liquid Chlorine is interesting. For the most part even during the panic the local Walmart had the Pool Essentials stuff for about $3.40 (which is usually good and fresh, but only 10%) the whole time that bleach was sold out. I did give a couple of neighbors the hint for their laundry and for "disinfectant" to just use half as much...

But that tells you the difference in the mindset here. I am glad I did the SWCG though.. now I only have to go through 3x the Muriatic (I wish it wasn't so) but that's still much easier.. I just with I could find it for $3.99 a gallon here.

The entertaining thing about TFP care is that it's basically like it was in the old days before stabilizer caught on. Who would ever think that less is more, eh?
 

Newdude

Gold Supporter
TFP Guide
Jun 16, 2019
6,351
NY
Try for a month just completing your projects by going to Home Depot or Lowe's but not both
I am convinced that their Algorithms know exactly what parts I need, and if they are out of stock I will buy 4 other parts to make it work the hard way. Why sell me one fitting when they can sell me 3 reducers, an elbow for the now needed clearance and 2 couplings ? That'll be $27 Newdude....
 

gregsfc

Bronze Supporter
May 27, 2014
204
Cookeville,TN
If I remember the results of the study correctly, the actual cya/fc nunber that brought the probability down to within EPA limits came out to be 22.5. The reasoning behind proposing 20 was for the industry to more easily manage things with a simple number. But how they ever got to 30 as "safe" based on the evidence they saw is beyond me.
 

gregsfc

Bronze Supporter
May 27, 2014
204
Cookeville,TN
I miss Menards. Midwesterners: Try for a month just completing your projects by going to Home Depot or Lowe's but not both-- and not Ace Hardware, and you will get what I mean. You mostly can do that with just Menards. I miss Aldi's too but there is hope if I stay here for that one, they are opening their first store in AZ two hours away. I have actually considered mail ordering stuff from Menards in some cases the cost plus shipping is less expensive... I am serious. Sad.

However the Midwest is different, especially with Muriatic Acid. It's use to do work there, etch concrete, clean up rust, etc. It's usually sold in onesies and it's cheap. Here it's marked "Pool" and sold as two bottles only (if you find one, it's $10) for $14-16 for the two bottles. The Liquid Chlorine is interesting. For the most part even during the panic the local Walmart had the Pool Essentials stuff for about $3.40 (which is usually good and fresh, but only 10%) the whole time that bleach was sold out. I did give a couple of neighbors the hint for their laundry

But that tells you the difference in the mindset here. I am glad I did the SWCG though.. now I only have to go through 3x the Muriatic (I wish itI just with I could find it for $3.99 a gallon here.

The entertaining thing about TFP care is that it's basically like it was in the old days before stabilizer caught on. Who would ever think that less is more, eh?
Using Chemgeeks HOCl chart, at 100 CYA, 3 FC would be "safe" with bacteria, but that would need to be the lower limit. I think they want 4 FC to give some room for the FC to be different in different parts of the pool.

Only thing is that they didn't base this finding on Chem Greeks math. I think showing them his math is what got him in the door. They actually set it up and found, at least in this set up experiment, which was peer reviewed, that the number needed was 22.5 to reduce that one deadly pathogen probability below the epa limit. I could be dead wrong. I was a business major.
 
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mgtfp

Bronze Supporter
Mar 5, 2020
780
Melbourne, Australia
Pool Size
66000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Astral VX 7T
Interesting...

Don't forget that Richard never used the algae-argument (which is the main driver for our CYA/FC ratio), he only ever argued with sanitation (even though we all know that getting algae under control is vital to ensure sanitation by FC not being consumed by algae and therefore remaining available to kill pathogens - but I guess that argument is less important in professional environments where you can enforce more stringent monitoring of FC levels).

I guess, the important information is on slide 20 of the presentation that gregsfc linked in his first post - here is the link again, so you don't have to scroll back:
https://www.cmahc.org/documents/CMA..._on_Stabilizer_Use._WAHC_2017-10-16_FINAL.pdf

The current MAHC limits allow 90ppm CYA / 2ppm FC (i.e. CYA/FC= 45), equivalent to about 0.009ppm of HOCl.

By going to CYA/FC = 20, equivalent to about 0.02ppm of HOCl, as per Richard's initial proposal, the risk for infections with Giardia would get reduced by a factor of 1.8.

Reading the infection risk from the graph shown on slide 17, the risk for infection with Giardia at the compromise they seem to be agreeing on (CYA/FC = 30, equivalent to about 0.013ppm of HOCl) gets reduced by a factor of about 1.4 - looks like they found their compromise right in the middle.

Infection risk for giardia seems to have been the most fruitful driver in these negotiations, as stated on slide 19: "0.12% risk from Giardia with current MAHC limits (2ppm FC, 90ppm CYA) gained the attention of the ad hoc committee".

Richards initial proposal would have reduced that risk to 0.06%, with the compromise the risk will only get reduced to 0.09% (which is below 0.1% - maybe that was the magic number?).

I suspect the real magic number was FC 3ppm. That's what the industry currently often states as the max FC level - many manuals for pool equipment specify that as the upper limit, the "ideal range" for guess strips is usually 1ppm - 3ppm. With the ratio of 30 for CYA/FC and cutting off CYA at 90ppm, they found a "scientific" justification to just stick to that range, the supplies industry basically doesn't have to change anything - apart from some fine print that FC 1ppm is only safe for CYA<=30ppm, FC 2ppm is only safe for CYA<=60ppm, and to make CYA 90ppm safe, FC 3ppm is required.

Richards initial proposal of demanding FC 4ppm at CYA 80ppm, would have meant that all the manuals and guess strip labels would have required an update - heaven forbid!

But the important step is that FC and CYA will no longer be regulated independently from each other, but to be maintained following a ratio. This finally acknowledges the role of HOCl as the actual sanitizing species in a chlorinated pool.

What is the impact of reducing the max allowed FC from 10ppm to 5ppm? Does that also affect residential pools in the US? Looking at our target FC, that would basically limit CYA to 40ppm for non-SWG pools and to 70ppm for SWG pools. During a SLAM, FC would be above the 5ppm limit for CYA>10ppm. That 5ppm limit certainly is a bit of backpedalling in acknowledging HOCl as the active sanitizer. I'd really like to understand what the reasoning behind that is.
 

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