Wait… Is This Normal in Your Pool?

Your pool can look perfect and still be one bad day away from turning. We dig into the “normal vs not normal” moments that confuse pool owners and even trip up seasoned techs, starting with the big one: chlorine that disappears overnight. When free chlorine drops to zero in 24 hours, it’s rarely magic and usually chemistry. We talk through cyanuric acid (CYA) targets, intense UV exposure, early microalgae you can’t see yet, and why high phosphates can quietly increase chlorine demand so your pool can’t hold a residual.

Next, we tackle the most misunderstood red flag in pool care: the strong “chlorine smell.” That odor is typically chloramines and combined chlorine, created when sanitizer binds to sweat, sunscreen, and other contaminants. We explain how to test free chlorine vs combined chlorine, what breakpoint chlorination means in real life, and how non-chlorine shock can help restore comfort and effectiveness, especially during summer bather load spikes.

We also break down why pH rises every week in plaster, gunite, and Pebble Tec pools, why vinyl and fiberglass can drift down, and how alkalinity, borates, water features, and saltwater chlorine generators influence the trend. 

• chlorine disappearing in 24 hours due to high CYA targets, UV, microalgae, phosphates, and low starting free chlorine
• why a pool should not smell like chlorine, plus what chloramines and combined chlorine mean for swimmer comfort and sanitation
• practical ways to reduce combined chlorine, including testing free vs combined chlorine and using non-chlorine shock
• why pH rises weekly in plaster, gunite, and Pebble Tec pools, plus why vinyl and fiberglass can drift the other direction
• how to slow pH rise with lower alkalinity targets, borates, and understanding aeration from water features and salt systems
• why salt levels change over a season, what counts as abnormal, and how rapid drops can hint at equipment issues or a leak
• when cloudiness after shocking is expected, how calcium hardness and pH spikes play a role, and why cal hypo clouds more than liqu

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Transcript

Welcome And What “Normal” Means

SPEAKER_00 1:03

Hey, welcome to the Pool Guy Podcast Show. In this episode, I'm going to go over what is normal and what is not normal in your pool. And I think you're going to catch on to where I'm going in this podcast as you listen. And again, there are some things that may appear normal, which are not, and some things that look normal, which are not normal. Are you a pool service pro looking to take your business to the next level? Join the pool guy coaching program. Get expert advice, business tips, exclusive content, and get direct support. From me, I'm a 35-year veteran in the industry. Whether you're starting out or scaling up, I've got the tools to help you succeed. Learn more at swimmingpoollearning.com. I'll start with this one. Is it normal for your chlorine to disappear overnight? And the answer to this is yes, in some cases, it is very normal for your chlorine level to disappear in one day or 24-hour period. And this can be due to a number of factors, and I'll list a few here that are the most common. The first factor, of course, and this is one that Bob Lowry talks about, and that is the 7.5% of free chlorine to cyaneric acid. And just to keep it simple, if your cyaneric acid is at 100 parts per million, that pool needs 7.5 parts per million of free chlorine, so that it's just going to be able to protect it from, of course, being destroyed by you know microalgae, anything in the water. So there are times when your pool may be at 3 parts per million. The cyanuric acid might be at 120 parts per million, and that three parts per million of chlorine is used up in that 24-hour period very rapidly fighting the microalgae in the pool. Now, this is algae that you can't see yet, hasn't formed completely. You don't see the yellow streaks on the wall. I remember one of my members, he had someone doing some work over in one of his accounts, another pool company, and they said, Yeah, yeah, this here he's not doing a good job because I see all the invisible algae there. There's a lot of algae in there, it's clear algae. He was trying to explain, I think, microalgae to the customer, which you couldn't see anyway, as a pool service provider. It's just his way of trying to get the account, because in you know, all intents and purposes, the pool was perfectly blue, and there was no quote unquote clear algae in the pool at that point. But microalgae can form and you can't see it, and this will consume the chlorine very rapidly. You could also have a high phosphate level in the pool. This is something that you can't test for with your standard Taylor test kit is something that will also destroy the chlorine level really rapidly in the pool, and that's why it's important to have phosphate test strips with you. You can see what the phosphate level, anything over 300 parts per billion should be treated because that will destroy the chlorine level pretty rapidly in the pool if you have high phosphates in the pool. It could also just be a low chlorine level, two or three parts per million, but it should be at five or six depending on that 7.5% formula. And you're having a really high UV index day. If you're in Texas, you know what I'm talking about with UV indexes, it's pretty extreme. And Bob Lowry says that a pool will lose about one part per million of free chlorine per day, just by the natural effect of different things on it in the environment. But if you have a really high UV UV day and the chlorine level is low at three parts per million, there's a good possibility that the cyaneric acid, no matter what level you have of that, is not going to be strong enough to protect it during that period, and that three parts per million will go down to zero within a 24-hour period or overnight, as the question was posed earlier. So it's one of those things where these are the most common factors where the chlorine level will be used up, stuff that you can't really see in the pool, stuff you can't really see in the environment, like the UV rays hitting the water, and it's something to be aware of. There are like outliers like iron in the pool water or nitrates, but mainly it's the these factors that are pretty normal in the summertime that cause the chlorine level to zero out within 24 hours. Here's another one. Is it normal for the pool water to smell like chlorine? And the answer is no, the pool water shouldn't smell like chemicals because chlorine really you can't really smell it. And what you're really smelling, and this is kind of like an ammonia kind of smell, like the Windex smell, and you're really actually smelling what's called combined chlorine or chloramines that are in the water. This is when the chlorine combines or binds with contaminants like sweat and sunscreen, other junk in the water, and this will of course give off this smell. Now you have to, of course, do a when you do your testing with the water, there's a free chlorine and a combined chlorine test that you should be doing, especially in the summertime. Fools that are being used, you need to do this. And they should be there should be no difference between the free chlorine and the combined chlorine. If you're using a photometer, it'll actually give you the combined chlorine number. So you take that number, and then of course you have to times it by 10 to get the breakpoint chlorine level of that. So shocking the pool using non-chlorine shocks will take away that odor in the water and get rid of the combined chlorine and make the chlorine more effective in the pool. So you shouldn't smell chlorine in the pool. I know when I go to hotels, I always walk by the pool and the spa area, and I can always smell the chloramines in the water in the summertime. Not a good thing, and I think it's something to be aware of that if you are using a pool and you smell a chemical, it's not really the chlorine you're smelling, but it's the combined chlorine or the chloramines in the water that make the chlorine ineffective. So it's really not particularly safe to swim in that pool because of the combined chlorine, and the actual free chlorine is really weak at that point, and there's a chance of you getting sick or ill because the chlorine is not effective in that pool. So, how do you prevent the combined chlorine in a pool? Well, it's really sometimes difficult because if you have a heavy use pool with people with sunscreen and other things that get into the pool from people swimming, it's going to destroy the chlorine level. So, one thing you can do before a heavy bather load is to put some non-chlorine shock in the pool prior to them swimming, maybe two or three pounds of it, and you can also shock the pool, bring it to about 10 parts per million, and then after the party, you can have the customer throw in a bag of shock or some non-chlorine shock, and just run the pool as long as possible prior to the party. During the party, the pool should be running as well, and afterwards as well. It's something that sometimes can't really be prevented to you know the degree that we want to prevent it, especially with pools with heavy bather loads. And it's just something that's really normal with summertime pool use. So you're gonna have some pools out there, especially if you do commercial pool servers with some combined chlorine in in that particular pool. Here's another one, and this one is it normal for my pH to rise every week? And this is something that in plaster and pebble tech pools, yes, it's perfectly normal for the pH to rise every week in the pool. Under nor normal circumstances, the pH is going to always be rising in the pool, these particular surface types. Now, I specifically want to separate the vinyl and fiberglass pools out of this discussion, because those pool surface types are just basically a piece of plastic and there's not a lot of acid demand created by these surface types. So you have to be cautious in a fiberglass or vinyl pool to keep an eye on that pH because it can actually drop in those pools every week, especially if you have bathers in there. The pH can tend to drift down. If you use trichlor tablets in a fiberglass or vinyl pool, which I don't really recommend you do, the pH can drift down very rapidly in that situation. So for those pools, you have the opposite effect. And I should say, is it normal for my pH to go down every week? It is in that surface type of pool, especially in the summer, with usage if you're using trichlor tablets as well. But for the those fiberglass for those non-fiberglass or vinyl pools, the plaster, gunite, pebble tech pools, it is normal for the pH to go up every week in in those pools. Now there are certain things you can do to slow the rise of pH. If there's water features, that's gonna cause aeration, which will cause the pH to go up in the pool. If you have a salt water generator, the cell itself has a lot of turbulence, plus the process that's kind of the process that the cell salt system goes through to create the chlorine also raises the pH in the pool. And it's something that's perfectly normal that happens. If you have a newer pool that was just plastered, for the first six months you're gonna have a really high acid demand, which means that the pH is gonna rise pretty rapidly in that new plaster pool. But just by normal standards, your pH is going to go up in those pools. Saltwater pools much higher and faster than non-saltwater pools, but it's going to rise. And there are a couple things you can do to slow down the rise of pH. One is to keep the alkalinity around 80 parts per million, and this will slow down the pH rising because the alkalinity will act as a buffer, keeping the pH from going up or down rapidly. And you can also add borates to the pool to 50 parts per million. By doing this, you also create a secondary buffer, which allows the pH to go to rise slower, I should say, and not go up as quickly. Another buffer that we don't talk about too much, but it does exist, and that's a cyaneric acid in the pool. Specifically, the cyaneric acid that's introduced into the pool as the trichlor tablets dissolve in the water. Half of these tablets are made up of cyaneric acid, which has a pH of two or three, and as these tablets dissolve in the water, the acid is released, cyanaric acid are released, and this also lowers the pH a little bit. So this it acts as a buffer to the water, and that's why in a vinyl fiberglass pool, trichlor tablets may lower the pH down to really corrosive and irritating levels for the bathers because of the cyaneric acid lowering the pH in the pool. So that's kind of how you kind of prevent a little bit of the pH from rising. But yes, it's perfectly normal for pH to rise in a pool every week because that's just kind of how it goes in the plaster and pebble tech pools, and in the vinyl fiberglass pool, it tends to go the other direction a lot of the times in the summertime. Here's another one here. Is it normal for the salt level in my saltwater pool to change over time? And the answer to that is yes, it's normal for the salt water level to change over a I wouldn't say a short period of time, but over a period of a month or so, you may see some fluctuations in the salt level. Now the salt doesn't evaporate out of the pool, but you can lose salt in the pool from backwashing if you have a sand filter or defilter, or if you the pool has heavy use and there's a lot of bathers and there's a lot of splash out. A lot of water splashes out of the pool, believe it or not, when you have you know a pool party, you may lose like half an inch in some cases. I've seen that before. And of course, the water will evaporate. And as you're adding fresh water, the salt water pool gets somewhat diluted in the wintertime. If you have a lot of rain, you know, 20 inches of rain, that will also dilute the water and reduce the amount of salt in the water by dilution. So the salt water, the salt water indicator at your system, it shouldn't show like 3400 parts a million one week and then 2600 parts a million the next week. That's really unusual for it to drop that much in a week or two. And that could be an indication that the salt cell is failing and it's not reading the right salt level, or there's a problem with the salt system itself. Now, if you have a leak, of course, you're gonna be losing salt as well, but you're gonna be losing other chemicals as well. And so that's kind of how you discover a pool leak with the salinity level, salt level dropping rapidly, the chlorine level dropping, you know, the pH and alkalinity going up, depending on how alkaline your water is, you're losing cyaneric acid. That indicates there's a leak in the pool. That's a whole nother problem. But salt in the pool will change, or you'll lose the salt level, it should go down over time. Nothing rapidly, again within a week or two, but the salt level does, of course, from the beginning of the season in May, let's say, to the end of September, you may see it drop from 3400 parts per million down to 2800 or 2600, and that's just normal. Splash out, backwashing, evaporation, filling with fresh water to kind of dilute the pool. All of these contribute to the salt level going down over the course of the season in most cases. Is it normal for a pool to turn cloudy after shocking? And this is one that yes, it is normal depending on which chlorine you're using, even if you're using liquid chlorine, which tends not to make the pool cloudy because it's liquid and the chlorine will just go into the water and not cloud up. But if the if the pool has a very high calcium level, it can actually cause a little bit of cloudiness because the chlorine does have initially a high pH when you're pouring it in there. So, very if you have a really high calcium hardness level, it can temporarily turn cloudy as the pH spike can cause the calcium carbonate to participate out of the solution. And this is kind of where you see the white cloudiness coming into the pool, is from that effect. Doesn't last very long, but it may last for an hour or so. And if you're pouring in a couple gallons of liquid chlorine, you may notice it even more with a pool with a again a very high calcium level. Again, the pH of the liquid chlorine will cause the calcium carbonate to participate out of water a little bit and cause that cloudiness, which will dissipate as the chlorine level kind of normalizes. Now, where it gets really cloudy is when you're using cal hypo, and this is something that you should be aware of, especially if you're gonna shock a pool before a party, like I mentioned earlier, that if you do use cal hypo, it will make the pool pretty cloudy if you you toss in two or three pounds of it in a 15,000 gallon pool. The pool may get extremely cloudy at that point, and this is kind of very similar to liquid chlorine because with the calhypo or calcium hypochlorite, you're adding a large amount of calcium to the water at that moment, and it may be at the calcium saturation limit, and that's why some pools you have more cloudiness than others, and you're gonna probably have some cloudiness with cal hypo in a pool, regardless, because you're adding depending on how much you add to the pool, I should say, if you're adding two or three pounds, you're probably adding more calcium than the water can actually absorb, and that's why it gets cloudy like that. And the cloudiness may last for a few hours, and so if there's a pool party happening that afternoon, I would advise against shocking that pool with cal hypo, use liquid chlorine. If you do use cal hypo, I would recommend turning the pool on, letting it run for 12 or 14 hours, and putting the cal hypo directly in the skimmer. You can also dissolve it in a bucket of water, but I find I find that that still will cause some cloudiness in the pool. So using cal hypo or even sometimes liquid chlorine to shock the pool will add some cloudiness to the pool. Now, if you wanted to use a chemical that's not going to cloud the water in those circumstances, I would suggest using dichlor. Dichlor is a granular chlorine that's half cyanuric acid and half chlorine. And this, in my in my experience, does not cloud up the pool. So before a party, you can use dichlor in the pool safely without clouding it. Now there are some really cheap dichlor shock bags that will cloud the pool-up, so just be aware of that. That the dichlor granular that you get in the buckets are the safest dichlor to use, and sometimes the cheap chlorine you know you get at Home Depot, no matter if it's dichlor or calhypo, will cloud the pull-up. So just be aware that every chemical has you know different manufactures, of course, and some have more byproducts than others. And you just want to get a reputable brand of cal hypo and dichlor, if you choose to use that to shock a pool, and you want to avoid extreme cloudiness in the water. But yes, the pool can get cloudy after shocking it, and it's something that's perfectly normal. So let the customer know that you shocked their pool, maybe cloudy for a few hours, and it's something that you have to explain because I've been guilty of not explaining this to customers, shocking the pool and then getting a message, you know, text message saying, Hey, my pool looks really bad after you left, it's so cloudy. You know, you gotta come back and fix it. Then I have to tell them that I shocked the pool and it's a normal you know byproduct of shocking the pool, it'll clear up in a few hours. So make sure you let the customer know that if you indeed make the pool cloudy, let them know it's just because you raise the chlorine level up really high, and that's just a reaction with the chlorine you use in the pool. Looking for other podcasts, you can find those on my website, semiapollearning.com. If you click on the podcast icon, there'll be over 1800 podcasts for you that are listened to. And if you're interested in the coaching program that I offer, you can learn more at poolcoaching.com. Thanks for listening to this podcast. Have a good rest of your week and God bless.