Industry moving toward CYA at or below 50 ppm

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ned8377

ned8377

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Apr 30, 2015
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Wake Forest, NC
I just got off the phone with Hayward. Wanted to know how they could recommend CYA of 60 - 80 ppm (80 ppm best) and chlorine of 1 - 3 ppm for the Aqua Rite. This is what it says on the face plate and is generally what other SWCG manufactures have been recommending. Most people reading this will know that the recommendations do not correlate with the FC/CYA chart in pool school. After asking my question the tech person immediately said that they are now recommending 30 - 50 ppm. He said that this is a new change they have made recently. He seemed to know what he was talking about. I was unable to find anything on the internet or any documentation from Hayward but did find the following which some of you may find interesting.

New Thinking: Chlorine/Cyanuric Acid In Balance - AQUA Magazine

And if you really want to go for a deep dive

http://www.lowrycg.com/wp-content/uploads/2013/05/Cyanuric-Acid-It-Controls-Your-Pool-rev03.pdf
 
I have to add to my last post as I just read the first article in it's entirety. This is a tremendous article. Much of it is very much what TFP teaches in the CYA/Cl chart under pool school. But what I really like about this article is basically putting that 7.5% number on where your FC should be maintained as a percentage of your CYA.

The really only new info is the 50ppm ceiling they are now recommending. There is no mention of those using SWG. But I always did wonder the rationale as to why those of us with one can maintain a lower FC at a higher CYA concentration. I was always suspect of that myself and as a result tend to err on running my SWG a little higher than recommended. Wonder if I am onto something there.

I want to hear others' experiences.

Edit: OP - you posted the same article twice. Did you mean for one of them to be a different article?
 
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I think the article was mostly for people who use pucks and for the most part don't know how much CYA they have and or don't understand the significance. TFP has always said that FC/CYA can be lower for SWG than for direct pouring of chlorine or having some sort of chlorine dispenser. I have never fully understood why but it has something to do with how the water is super chlorinated as it passes through the cell and is able to kill everything because the chlorine level is much higher inside the cell than after it leaves the cell or gets out into the pool. One thing interesting to me was that the article essentially said that if your chlorine level is high enough to get rid of algae or keep it at bay then you don't have to worry about bacteria etc.

- - - Updated - - -

Here is the paper the Robert Lowery did on the subject. CYA not only affects chlorine but also affects TA and PH as well as the saturation index.

http://www.lowrycg.com/wp-content/uploads/2013/05/Cyanuric-Acid-It-Controls-Your-Pool-rev03.pdf
 
To those of you who are a bit new, this is Richard Falk's work. Chem geek has long been the "go to" resource for this FC/CYA ratio.

I applaud Lowry for getting this idea in an industry publication but the credit for these ideas goes to Richard Falk and Ben Powell. Jason Linhart (Jason Lion) also gets credit for a great deal of verification of chem geek's ideas.
 
I thought Richard Falk was indeed Chem geek. I thought I recalled that from years ago when I first joined the forum. I don't think anyone is belittling anything from these guys. As a matter of fact when I was reading the article I was thinking to myself: "Gosh this sounds like it was written by a senior member of TFP" as I have been reading this for years right on this site.

But some experts need to start chiming in on this 50 ppm ceiling they are recommending. Especially for those of us with a salt cell that has been told to go "higher" just because the forum says so. I just took my CYA to 80 ppm as recommended here. Now after reading this article, I am concerned.
 
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mikemass said:
I thought Richard Falk was indeed Chem geek. I thought I recalled that from years ago when I first joined the forum. I don't think anyone is belittling anything from these guys. As a matter of fact when I was reading the article I was thinking to myself: "Gosh this sounds like it was written by a senior member of TFP" as I have been reading this for years right on this site.

But some experts need to start chiming in on this 50 ppm ceiling they are recommending. Especially for those of us with a salt cell that has been told to go "higher" just because the forum says so. I just took my CYA to 80 ppm as recommended here. Now after reading this article, I am concerned.
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No need to be concerned in my opinion. This is an area that has been in transition for years. As Dave points out Richard Falk did the scientific work the article is based on. He is also the one that worked with Jason Linhart in creating the tables we have and use today.

I see it more of baby steps of the industry catching up with what a pool maintenance guy (Ben Powell) saw happening with pools he took care of and started asking questions. A lot of people deserve credit for creating what we have today and I'm sure the industry will slowly catch up. But, with that being said, there is lots of money involved so who knows what may happen.
 

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mikemass said:
I thought Richard Falk was indeed Chem geek. I thought I recalled that from years ago when I first joined the forum. I don't think anyone is belittling anything from these guys. As a matter of fact when I was reading the article I was thinking to myself: "Gosh this sounds like it was written by a senior member of TFP" as I have been reading this for years right on this site.

But some experts need to start chiming in on this 50 ppm ceiling they are recommending. Especially for those of us with a salt cell that has been told to go "higher" just because the forum says so. I just took my CYA to 80 ppm as recommended here. Now after reading this article, I am concerned.
Click to expand...

tim5055 said:
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No need to be concerned in my opinion. This is an area that has been in transition for years. As Dave points out Richard Falk did the scientific work the article is based on. He is also the one that worked with Jason Linhart in creating the tables we have and use today.

I see it more of baby steps of the industry catching up with what a pool maintenance guy (Ben Powell) saw happening with pools he took care of and started asking questions. A lot of people deserve credit for creating what we have today and I'm sure the industry will slowly catch up. But, with that being said, there is lots of money involved so who knows what may happen.
Click to expand...

As Tim said, I wouldn't be concerned. I've been keeping CYA at 70-80 (my AquaRite manual says 60-80) since 2004 without issue.
 
Tim5055 says it just right. This is the very backbone of TFP stuff that the industry is only recently coming around to. The 50 ppm is (I think) some kind of "safety valve" Lowry put in there and it is simply unwarranted.

Chem geek and Jason Lion are the guys that worked this out and a 50 limit to CYA was never part of their research to my knowledge.
 
Agreed. There is nothing new or earth-shattering here except for the fact that the industry is finally pulling it's collective head out of its [...TFP Decency Filter...]!

Ben Powell, Richard Falk & many others (including the principals that started TFP) deserve A LOT of credit for putting science and reason where there wasn't much more than legend and old-wive's tales.

As for the 50ppm limit on CYA, HOGWASH! Chlorine loss in a clean swimming pool is ENTIRELY dominated by UV photolysis of hypochlorite. Having higher levels of CYA in an SWG allows the cell to work less to produce and maintain adequate FC levels. Arbitrarily lowering CYA levels simply degrades SWG cells faster and shortens their lives for absolutely no good reason. There is no evidence whatsoever that CYA levels around 100ppm have any negative effects and the contribution of cyanurate species to total alkalinity is marginal at best. As long as the total alkalinity is corrected for this (which Pool Math does internally so as to save the user time), then the CSI value calculated is valid.
 
Thanks for the post, and the very interesting read. I just joined, and so glad I did or I would be burning through the trichlor pucks, like everyone else I know. I was so close to buying a chlorinator when I switched from Bromine when I did a liner change. I had no idea what CYA was until I started to do a bit of research on the conversion from bromine to chlorine and came upon an old post on this forum. The idea about CYA levels frankly scared me, so I continue to read to learn more, and happy I joined. Just got my T2006 today and haven't had a chance to use it as I got home after dark. Any suggested videos to watch to help me become familiarized.
 
Her pool boy said:
Thanks for the post, and the very interesting read. I just joined, and so glad I did or I would be burning through the trichlor pucks, like everyone else I know. I was so close to buying a chlorinator when I switched from Bromine when I did a liner change. I had no idea what CYA was until I started to do a bit of research on the conversion from bromine to chlorine and came upon an old post on this forum. The idea about CYA levels frankly scared me, so I continue to read to learn more, and happy I joined. Just got my T2006 today and haven't had a chance to use it as I got home after dark. Any suggested videos to watch to help me become familiarized.
Click to expand...

There is a link to videos on http://www.tftestkits.net
 
But some experts need to start chiming in on this 50 ppm ceiling they are recommending. Especially for those of us with a salt cell that has been told to go "higher" just because the forum says so. I just took my CYA to 80 ppm as recommended here. Now after reading this article, I am concerned.
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Pool Water Chemistry

This thread is a "deep end" article which is about as heavy as they get for us non-chemists. It is long, but you can use your browser to 'find' on the term "SWG" which will take you to many references. You'll find that it's based on decades of experience and is science-based wherever possible. It's written in a respectful manner with full disclosure of knowns and unknowns. I hope it's helpful, and I think SWG owners will remain satisfied with TFP's recommended CYA levels.
 
It's not the high CYA in and of itself that I am expressing concern over. It's the statement TFP claims over and over again that you can run a lower FC level with a Salt system than you can with non SWG pools.

Let's say Powell's claim that the 7.5% guideline holds true. If I am running an 80 PPM CYA with salt, the Cl/CYA chart says I should run FC between 4 - 6. In %'age terms that is 5-7.5%

Needless to say I am going to err on the high side of that range for my piece of mind. Which actually puts me in the non-SWG range of 6 - 9ppm FC (7.5 - 11.25%)

What no one has addressed is why it is recommended to run a lower FC with salt at the same CYA than with non-salt other than: "It's just the way it is". Maybe in the archives of this site there is a sound reason to this. But everything I always remember reading is something along the lines: "It seems SWG users can get away with a lower FC." Even on the Cl/CYA page it states:

Most saltwater chlorine generator (SWG) pools appear to prevent algae at a lower minimum FC level compared with the minimum FC column for manually dosed pools.
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I'm a "WHY" kind of person. Because definitive answers help give me more acceptance. It's that "appear" word above that isn't exactly scientifically convincing to me. However the article(s) posted in the first post of this thread is VERY convincing to me.

As a final question: If exceeded usage of a Salt cell (running at 90+%, longer pump run times, etc) in order to maintain a higher FC as required with a higher CYA shortens the life of the cell, then why wouldn't I want to run a lower CYA, thereby maintaining a lower FC? Less run time, less output %'age on the cell = longer life?
 
Correct me if I'm wrong, but as I've understood.. getting by with the lower FC with a SWG has to do with the consistency of generating chlorine, vs a 1 time per day with manual dosing. Manual dose=higher to make sure FC never gets below the bottom parameters. SWG= consistent, all through the day & night dosing, depending on run times & percentage, obviously. This is my simple way of understanding it.
 

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