Bob Lowry Why High Cyanuric Acid Makes Chlorine Weak

Welcome And Why CYA Matters SPEAKER_01 1:04 Hey, welcome to the Pool Guy Podcast Show. In this episode, I have another best of Bob Lowry, where Bob Lowry talks about high cyaneric acid, the reasons why it's not good for water balancing, and since he's a chemistry expert, I think you should really listen carefully to why high cyaneric acid is not a good thing for Coaching Program And Support Pitch SPEAKER_01 1:25 your pool. Are you a pool service pro looking to take your business to the next level? Join the pool guy coaching program.

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What Cyanuric Acid Actually Does SPEAKER_01 1:45 And that brings us to the subject of the CYA debate. Now there's some that say that, well, we can first meant talk about what exactly is cyaneric acid. One question I get all the time is why is it referred to as conditioner or stabilizer, besides using that, using the chemical name, the cyaneric acid name? Why is it in the industry do we call it a conditioner or a stabilizer?

SPEAKER_00 2:08 Cyaneric acid, by the way, was was brought to the pool industry in in 1956. And shortly thereafter, they chlorinated it and made it into a granular and then eventually compressed it into a tablet. And a tablet became a great thing. But cyanuric acid was a great thing in the beginning.

They thought that the only thing that it did was it slowed down the UV or sunlight degradation of chlorine in water. And chlorine, if you just put liquid chlorine or straight chlorine into water and make the killing form of chlorine, then the degradation of that is about 75% in two hours. And then in the next two hours, it's 75% of that. So you can see that pretty much in four hours the chlorine is gone.

In the 1950s, if you had a pool guy that serviced your pool, he came to your pool every day because the chlorine he put in yesterday was gone. Pool guys couldn't take care of too many pools because they had to come to your pool every day. And so there wasn't a thing like a weekly call. But as soon as they developed cyanuric acid, introduced it, started selling it as a as a dispenser for chlorine, it took off like a jet and became the most popular chlorine in the in the industry, and probably still is to this day.

In the beginning, it caught the rest of the chlorine manufacturers unaware. And as a result, there was all kinds of rumors going around in the 50s and 60s and continue to this day that it will lock up all of your chlorine and uh so that your chlorine won't work at all, and you can get cancer from it. And I mean, there had just been one thing after another to try to displace it. I think the competitors started most of that.

But in any case, those rumors still persist. But now that we have better technology, better understanding, and and better methods of testing and things, we've been able to dig into this a little bit deeper. But the fact is that that we call this product a stabilizer, a conditioner, because it stabilizes chlorine against UV degradation. And in fact, using as little as 30 parts per million of cyanuric acid in the water will keep the chlorine in the pool eight times longer than without it.

And so that is huge. And if you had cyanuric acid in the pool, it would last a week, eight times longer. So it it is a a magic chemical from that standpoint. How CYA Binds Most Chlorine SPEAKER_00 5:34 But what we overlooked, because I went back and looked at the information, since about the mid-1970s, we have known that cyanuric acid and chlorine actually bond together in the pool.

And there's only a very small percentage of the chlorine that is not attached to cyanuric acid. And it doesn't mean that when it's attached to it, it it's not available. What it means is that the amount of chlorine that is available in the water is in an equilibrium. And even though it's a small amount, when some of that chlorine that's free gets used, some of the chlorine that's bound to cyanuric acid instantaneously converts over to the killing form of chlorine.

It's like it's not all available right now, but all of the chlorine that's in your pool is always will be available until there's none of it left. But the percentage is very small. The percentage, even at around 30 to 50 parts per million of cyanuric acid, only 3% of the chlorine is available. 97% of the chlorine that's in the water is bound to cyanuric acid, provided you've got more than 30 parts per million of cyanuric acid in the pool.

If you get up to about 100 parts per million of cyanuric acid, there's only two percent of your chlorine that's available. And God forbid that you should get up to 150 or 200 parts per million, because then there's only about 1% of your chlorine that's available. SPEAKER_01 7:27 I think that points out the next part that I was gonna ask you is the cyaneric acid level is probably the number one factor on the effectiveness of chlorine in the pool, is that correct? SPEAKER_00 7:39 That's right.

The rate of killing, the speed, and the duration of killing is all controlled by the cyaneric acid. And it's a good thing, but too much of it is a bad thing. CYA As A pH Buffer SPEAKER_00 7:54 So we need some to protect chlorine from sunlight and so on, but we also need to understand that it's not just a chemical that protects chlorine from sunlight, it it is a a buffer, and it's actually quite a good buffer, against the pH going down. So it's a good buffer in the water to keep the pH from going down.

So it acts in conjunction with the alkalinity in the pool, which is also a buffer. And it's the total alkalinity keeps the pH from going down. And so those two are the buffer system against pH going down. We know if you've studied a little bit, you know that there is an adjustment that needs to be made to the Langolair saturation index because of cyanuric acid.

And in general terms, you take one-third of cyanuric acid and subtract it from the total alkalinity reading to get what we call carbonate alkalinity. SPEAKER_01 9:27 I think it's important to note too then that cyanuric acid not only affects the chlorine, but again, you mentioned it's a buffer to pH, so the reason why you need to do the adjusted alkalinity, it affects more than one part of the water. SPEAKER_00 9:39 It controls the killing, it controls the it it controls the pH from it going down, and it keeps chlorine from being destroyed by sunlight. So it is it it does a number of things that we that we really uh didn't think about when they originally put it in the pool back in the 50s and 60s.

SPEAKER_01 9:58 Yeah, and I think one of the things that is surprising in this era is that there's really no effective way Lowering CYA Drain Versus Alum SPEAKER_01 10:05 to eliminate it or reduce the level except partially or fully draining the pool. I know that there are some chemicals on the market, bioactive and natural chemistry have a cyaneric acid-reducing chemical. And I know that Rudy Steinkowicz talks about using aluminum sulfate to reduce the level. But, you know, as far as science goes, and as far as the the chemicals that will counter cyaneric acid, is draining the pool the only way to actually get rid of it?

SPEAKER_00 10:33 It's it's probably the the cheapest, fastest, and most effective way is just to drain some of the water and fill it back up. And because tap water doesn't have any cyanic acid in it, we we can pretty much drain whatever percentage of the pool we need to get back down to to 50. So if you have a hundred in your pool and you want to get to fifty, you drain 50% of the water and fill it back up and you'll be at 50. So that's the most effective.

But you can use alum, and what they've said is that a percentage, which uh is strange, but because most chemicals you add an amount and you get an expected precipitate or an expected amount that comes out of the water, and it's on a molecular basis is one for one. So we're able to to calculate that. But people are saying that you know they're i no matter where they're starting cyanuric acid is, they put alum in and 50% of it's gone. And I just I find that a strange, a strange thing as a chemist that that that happens.

But nonetheless, it does appear to lower cyanuric acid some, but then you end up with alum and the precipitate of cyanuric acid on the bottom of the pool. And you're gonna be adding something like eight pounds for each 10,000 gallons of alum to the pool. So if you've got a 20,000 gallon pool, you're gonna put in 16 pounds of alum, and then you're gonna put in, it's going to precipitate another eight pounds of cyanuric acid. And so you're gonna have 24 pounds of stuff on the bottom of the pool.

And it doesn't, because the alum makes what we call a flock, the flock is uh like a feather in air. It's the same thing. It's kind of a a very light, spread-out leaf-looking thing that is in the bottom that that only that takes hours to settle. You put the alum in the pool and mix it up and then let it settle for something like 12 hours.

And once uh at the end of 12 hours in the bottom of the pool, you've got about six inches of stuff in the bottom of the pool. And then you need to vacuum that to waste, and you have to vacuum it very slowly because if you move the vacuum very quick, it resuspends the the alum flock, and so you don't get it sucked up into the vacuum. So you have to vacuum very slowly. Well, when you vacuum very slowly, you know, you may end up losing 800 or 1,000 gallons of water out of your pool just from vacuuming, because you have to vacuum to waste.

And then there's one concern that someone has raised, and I'm not one of them, but someone has said it that it leaves aluminum in the pool. There is a an EPA drink a drinking water standard on the amount of aluminum in pools because they think it has something to do with with Alzheimer's and dementia. So at any rate, it does, there's a potential to leave some aluminum in the pool. SPEAKER_01 14:08 I think the bottom line is that draining and refilling is probably the safest and most effective still.

SPEAKER_00 14:13 So well, you can see how much work it is to use alum, and you know, if you're going to drain your pool, you either set your pool equipment onto waste, or you know, you put a pump in it and pump some of it out, and you're done. You don't have to you don't have to add the alum and mix it up and vacuum to waste and do all that stuff. So, and then when you're done with alum, you end up having to readjust your alkalinity and your pH because it changes it. SPEAKER_01 14:39 Yeah, and I would say, you know, that's that makes it more complicated for sure.

And one thing I think is pretty well known in the industry, it may not be known by everybody, but the fact that cyaneric acid does not evaporate out of the pool when you lose water, so it just stays in the pool, and that's why the level keeps increasing. And one thing that I've recently was brought to my attention, someone posted this in in my group, and it it was originally, I think, on the Arenda Why CYA Builds Up Over Time SPEAKER_01 15:04 blog. It is by Richard Falk. And the quote goes something like this.

I'll read part of it, or maybe all of it. It says, also in all pools using pools using CYA, chlorine slowly oxidizes CYA itself. At normal warm pool temperatures, the CYA loss is around three parts per million per month, and it takes 2.5 parts per million free chlorine to oxidize one part per million of CYA. Um, some pools show higher loss mostly due to high temperature and higher pH that accelerates this reaction.

You know, based on this quote by him, is it accurate to say that the chlorine can oxidize CYA at higher temperatures? SPEAKER_00 15:41 It does, but the amount of the amount is small enough that it it's it's probably not even something you can measure. You know, you're looking at maybe at maybe five ppm a month in the summer when you're using the pool and you've got a higher chlorine level. Yeah.

And and so it's really not very much at all. And and you know, especially if you're using trichlor, you're putting back more than that every week anyway. You know, in a in a typical pool, you're probably putting 20 to 30 parts per million of cyanuric acid into the pool every month in the in the summer. And if the degradation is only five, you know, you're you're far behind what could do.

And I I looked into seeing if we could actually run the chlorine level up high enough that it would kill off the cyanuric acid level. And I went all the way up to 200 parts per million of chlorine, and it still didn't wipe out the cyanuric acid. So it's a pretty hardy molecule. Cyanuric acid wasn't invented in 1956, it was actually discovered in the ground in around 1900 around cattle.

You know, cattle, when they they poop on the ground, it contains some chemicals that are similar to fertilizer. And fertilizer is kind of one of the starting chemicals to make cyanuric acid. So in the stomach of a of a cow, they actually make cyanuric acid to a small degree. To a small degree.

So it's not that. But so and that of course raises the question where somebody said it was was cancer-causing and caused the industry to go crazy around 1980, and they had to repeat a lot of the test to prove to everybody that cyanuric acid was not cancer-causing. SPEAKER_01 17:48 Yeah, so I think back to that quote, I think the dilution probably you know from evaporation, because you do add fresh water to the pool. SPEAKER_00 17:56 Evaporation doesn't lose any cyanuric acid, but because evaporation is like distillation, only a lot slower.

And so when the water evaporates, only pure water evaporates. All the calcium and sodium and everything that's in the pool stays there. And then when you add more water, that stays there again. So all the stuff in the pool keeps building up.

That's why your TDS builds up and your cyanuric acid builds up because you keep, you know, using the cyanuric acid and adding more, and it keeps building up. The only thing that loses cyanuric acid or any other constituent that's in the pool is water loss. And water loss, of course, can be from a leak or splash out or drag out or filter backwashing. But aside from that, unless there's a water loss, you're not you're not lowering cyanric acid.

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Thanks for listening to this podcast. Take a rest of your week, and God bless.