Cold Plunge Pools and Cold Water Chemistry

This week, Andrea flies solo while Paulette takes a much-needed break—and the result is a fun, educational, slightly unhinged deep dive into cold water season, winter chemistry, dry skin survival, and why cold pools can actually make your job easier (yes, really).

From frozen reagents to stain treatments to elderly Floridians complaining about “cold” 78-degree pools, this episode is a full winter-route mood.

Episode Summary

Andrea kicks off the show explaining why cold water is basically a superpower for stain removal—and why winter is the perfect time to hit those stubborn stains before the pool closes or before the last brave snowbird gives up on swimming.

Then she pivots to the real pain of winter service: dry, cracked, chlorine-blasted pool-tech hands.
Andrea drops her holy-grail products for surviving winter route life:
• Aquaphor (the OG skin savior)
• Gloves in a Bottle (a “liquid glove” that doesn’t magically repel water but helps keep your skin intact)
• Cheap leather gloves you won’t cry about when chlorine eats them alive

With the hand-care PSA complete, Andrea dives into the meat of the episode:

Cold Water + Chemistry = Chaos

Cold water messes with your testing, your reagents, your strips, your readings… everything.
She covers:
• Why frozen reagents sometimes survive—if you treat them right
• Which false readings are the most common in winter
• Why cyanuric acid tests lie in cold water
• How pH and alkalinity reactions slow down
• Why test strips get stupid below 45°F / 7.2°C
• The right way to warm a sample before testing (hint: NOT the microwave)

She also explains why, according to Taylor, if the water is too cold for accurate testing…
you technically get a pass.
(Andrea delivers that part with the exact level of sarcasm you’d expect.)

Cold Water Perks You Didn’t Know You Needed

Yep—winter has pros:
 • Stains lift easier
 • Algae struggles to survive
 • You might use fewer chemicals
 • Nobody’s swimming, so nobody complains (except the heat-pump HOA)

Andrea also wanders into…
 • evaporation math
 • energy loss
 • bubble covers
 • liquid solar covers
 • ducks getting annoyed
 • Florida people who think 45°F means the end times
 • commercial pools with 200,000 gallons of lukewarm regret
 • spa cold-plunge chaos
 • why solar panels leak out of spite

Her tangent game is elite this episode.

Key Takeaways

• Cold water interferes with nearly every test, from alkalinity to CYA—warm samples before testing.
• Frozen reagents aren’t always ruined, but they must thaw naturally and pass the “crack and floaty” check.
• Stain treatments work better in cold water, so winter is prime time.
• Evaporation steals heat energy like a thief, and even an inch of water lost has a huge thermal impact.
• Solar covers can actually add heat—not just retain it.
• Liquid covers work… mostly. Don’t expect miracles.
• Cold water means less algae, fewer chemicals, and fewer complaints—unless you service Florida.
• Winter equals crusty pool-tech hand

Transcript

Speaker 1 (00:00)
cold water is really great for treating stains.

So that's when you wanna do your stain treatments, because it's make those stain treatments much more effective. Also, since the water is super cold, no one's gonna be swimming in any way, so you're not really losing any swim time for your customers.

That's, you know, assuming of course that, well, I mean, I guess, I don't know. but before you close the pool, you could do a stain treatment. I don't know if you guys do that. Let me know. Let me know if you do stain treatments before you close them.

Hello, hello, hello. Is anyone there? Just kidding. Hey, what's up everyone? It is me, it's Andrea. I'm your favorite pool girl and I am coming to you solo today because my mother needed a break. So I hope everybody has had a great weekend. It's getting colder, pools are closing.

All the snowbirds are coming down to us in Florida, which is great. Love, love the snowbirds. So I just wanted to get on here and just talk about cold water. Cause we're all experiencing that right now. Even us in South Florida, where it's still kind of warm out depending on the day and also depending on the time of day. But we're getting into the winter season here and I just thought I would.

You know, go over some stuff and hopefully this is interesting. Hopefully this will help you guys out. so let me just start by saying that if you are like me and you put your hands in the pool water multiple times a day, you get dry skin. And if you don't get dry skin and you're not like me,

Love that for you. Please tell me your secret. How does it feel to be God's favorite? I don't know what to say about that. So one of the things that I use to protect my hands from getting dry and cracked skin and just being all around uncomfortable in general. If you guys do not know about aquaphor.

I'm telling you about it now. All right. So go and get you some. I've tried the generic brands and they're okay. The aqua four is a little bit like the actual brand name. I don't know. I don't, I don't read like ingredients and formulas and stuff. There's just something a little bit different about it. but aqua four will literally take care of any dry skin problem that you have, whether it be if you, if you

touch too many tabs throughout the day and you don't wear gloves and your fingers get all crusty. Aquaphor helps a whole lot. It also helps if you get like heat rashes or like just your skin is moist all the time and it gets irritated. The aquaphor really helps. Another thing that helps is the stuff called gloves in a bottle.

And it is a, it's a lotion and it's not like waterproof or anything. So you're still, you know, you put it on your hands, you rub it in your hands and you, it's not like your hands are going to repel water or anything like that. It doesn't work that way, but it just kind of helps. so what, well, what I like to do is I'll put on regular lotion and then I put on the gloves and a bottle lotion and it kind of just like seals everything in and gives you a little bit of a protection.

It's a little bit more waterproof than a regular lotion. But again, it's not like You're you're still gonna feel The cold temperature of the water or if it's warm, you're not it's not like an actual glove But you're you know, kind of like liquid cover which I'll get to you later So those are my and gloves obviously actual regular gloves so you can just get what I I like to do is just buy the cheap pairs

so that when they get shredded by the chlorine or they start to fall apart or whatever, could just go buy another pair. You know, and it's not that, it's not that painful for your wallet. Now, if you want to invest in a nice pair, I'm not going to stop you. Please feel free. Obviously grown people can spend their money on whatever they like. So if you want to invest in index in an expensive pair, that would be fine with me. I give you permission.

But I do like to have, just like some cheap leather ones, as I said, just because not even so much for the water, but more for the, my, I use a metal pole. use an aluminum pole. So that gets very cold. And also, the metal components of my riptide cart, you know, the handle and all that stuff gets pretty cold. First out for South Florida. I can't imagine what it must be like for you Northern people. I.

I could never, I would literally die just I think from the dry skin alone, I would die from that. So those are the first two things. And those are just kind of like, you know, my little, my little personal tips to you from me. So here's

The important stuff, okay? Now if you are out there testing and testing water and servicing these pools and it's, you know, I think the coldest that it's been so far this week, it was in the 40s in the morning when I woke up. And then by the middle of the day, it got up to, you know, the mid 70s.

So yeah, 45 in the morning for me in South Florida is freezing. is Arctic tundra. It is like I need an igloo. need a snowsuit. I need some whale blubber to keep me warm at these pools. And I do realize that it's much colder in other places. But this goes for everybody. So when you are out there testing,

these cold, cold, frigid, icy pools. You have to keep in mind a couple of things about your reagents. If you are using our favorite blue box test kit, if you're using strips, it affects those too. The meters, the photometers are not really affected by cold water. So here are some tips.

if you use the liquid drop reagents as I do. So first thing, know, just to remember that same thing with your furry friends and maybe your human friends. If you were cold, if you're cold, they're cold. So you need to bring them inside. So you can keep them in the cab of your test, your test kit. You can keep your test kit in the cab of your truck.

if you don't already, some people do that, you know, to keep them safe from burglaries. Also, I do it sometimes when I know it's really, really, really hot outside. I don't like to leave it sitting in the back of the truck all day. I'll bring it inside. but if it is cold outside, if it is cold enough to where things are freezing, or even slightly before that, you want to keep them stored, somewhere where it's not freezing somewhere nice and warm.

Now, if you have a frozen reagent, don't need to toss it right away. It still might be okay. Just because it's frozen doesn't mean you have to toss it.

What you want to do is let the reagents thaw and you want them to thaw naturally. You don't want to, you don't want to microwave them. You don't want to put them in any kind of warm water. Don't try to like put it in an oven. I don't know. I don't know who would do that, but yeah. So just let it thaw naturally. You don't want to speed it up. Okay. Don't don't introduce heat.

Into the equation is what I'm trying to say because the will destroy the reagent. Then the next thing you want to do is you want to check the bottle. I'm a little sniffly I apologize check the bottle for any cracks or you know if it's leaking somewhere. Obviously frozen things expand so it might have compromised the plastic of the bottle.

And then you want to inspect for floaties or particles or anything generally weird with the reagent that is normally not there. So if you see, you know, little bits floating around, then you want to toss it.

So yeah, so there we go. Check for cracks, check for leaks, check for particles that shouldn't be there. If you see those things, go ahead and toss it. If you don't see any of that and you're back to liquid, then you're good to go. Now,

Cold water will interfere with your test results.

So for example, it might take a couple of extra drops in your alkalinity test, in your total alkalinity, or in your calcium hardness test.

before you get a reaction, before you see the color change.

Speaker 2 (10:11)
you

Speaker 1 (10:12)
So you could end up with a false high reading for alkalinity or calcium. You know, it's not super detrimental.

But you you just, want, you want to be accurate and you want to have that accurate accuracy because if you got a false high calcium, maybe you think you need to drain the water or something like that, you know, and replace it and you actually don't. Or, you know, with alkalinity, if the alkalinity, you, it's a false high, you might be adding too much acid to counteract thinking that you have this high level and you actually don't. So it's really important.

So in a pH test, some reagent components may precipitate when the reagent is added to a low temperature sample, and that can cause faded test colors, just an inaccurate reading in general, and, or no reaction at all. It might just be clear instead of red, and that will be confusing because it's supposed to be red, or pink at least.

And then with the cyanuric acid test, stabilizer, conditioner, that guy, testing of, excuse me, low temperature water will provide false low results. And this is even, this is even for water that is in like the sixties, like it will, it can still, so what happens is it, the speed at which the precipitate forms,

is slowed down. So it's not going to get cloudy as fast. So you could be getting a false low.

Because it's not you know, you mix it up for a second and use you you measure how cloudy it is based on how Visible the dot is right? Well, if it's too cold, it's not going to get cloudy. It's gonna stay clearer longer and so you might have a 40 but you think it's like a 20 or a zero or whatever because the reaction time is slowed down

So that's bad because that's gonna obviously cause you to add stabilizer when you didn't need to. And then you're gonna come back and not have any chlorine because your stabilizers at a hundred or whatever, you I'm just speculating here, who knows? But yeah, so that can be problematic. That can be problematic. And then as I said a little bit ago, test strips are also affected by lower temperatures.

specifically temperatures lower than 45 degrees Fahrenheit or at 7.2 degrees Celsius for my Australian friends. and my UK friends too, as well. Of course I just have more Australian listeners anyway. Yeah. So even if you use test strips, you still have to be careful. And then, so what should you do?

if the water is really cold and this applies to cold plunges as well not just like winter water if you service cold plunges you need to be aware of all of these interferences and everything as well so what you want to do is take your water sample and bring it you know inside your truck or inside of a building or something like that and let it warm up for a minute before you test it.

And then if it is colder than that, or it just doesn't warm up fast enough for you, guess it's not recommended according to Taylor to test water that is that cold. So it seems like Taylor has given you a pass. Not to skip your responsibilities. Come on people. I'm just joking. But I mean, if you, if it's not possible to get an accurate result,

Why do the test?

Next on the list, next up, cold water is really great for treating stains.

So that's when you wanna do your stain treatments, because it's much easier And this will make those stain treatments much more effective. Also, since the water is super cold, no one's gonna be swimming in any way, so you're not really losing any swim time for your customers.

That's, you know, assuming of course that, well, I mean, I guess, I don't know. No, nobody, nobody's doing that stuff in the snow, obviously, but before you close the pool, you could do a stain treatment. I don't know if you guys do that. Let me know. Let me know if you do stain treatments before you close them. Andrea at talking, wait, Andrea dot talking pools at gmail.com is my email address. And I just reminded myself.

that I did get a couple of emails I need to go check and I will read those on the show next week. So if you sent me an email, thank you for that. I did recently see it. It turns out I wasn't logged into that email address on my phone. So I did miss a couple, but don't worry. I'll get to you. Sorry for that side track.

So now I'm not going to, like, I wanted to talk a little bit about heating and stuff like that, but I'm not going to sit and talk about the different kinds of heaters and what they do and all that stuff. Cause maybe that's for another episode. I don't know. We'll see. So what I wanted to explain was something that not was really confusing, but it was just one of those things. Well, like, why did they call it that? So I always hear about energy loss, the pool loses energy.

the energy loss of the, the, why aren't they just say heat? I don't know. I don't whatever. I'm just, I'm just kind of joking. I don't need anyone to explain that to me. So anyway, energy losses, I got no one else to talk to. She's gone talking to myself here. So the energy content of a pool is determined by the temperature of the water. So the water becomes colder when energy is withdrawn.

and it becomes warmer when energy is added at a rate faster than it is withdrawn. And then we have a couple of different types of energy losses. You know, I love a good list. So we have evaporation, convection, thermal radiation, and conduction. So the first three that I listed, evaporation, convection, and thermal radiation, those occur at the surface.

of the water. So, you know, evaporation, we all know what that is. That's when, you know, things are different temperatures and the water turns to vapor. Convection is, think of, think of blowing on a, like a, like a soup. If you blow on your soup, you know, to cool it off, that is convection. Also, convection is when

If you get out of the water and then the wind like air blows on you and you feel cold, that's convection. And then you have thermal radiation, which is think of like a fireplace, you know, it warms the room that it's in. Similar concept. you know, there's heat radiating off of the water that's warm. And then you have conduction, which does not occur at the surface.

And this happens in the plumbing or the structures of the pool.

That's not a very high source of energy loss, or the energy loss there is very low compared to the other three. So the other three heat losses, those make up for about 95 % of the energy loss in a pool. And then the conduction accounts for about 5 % of that. So it's minimal, but it still affects things. Another way that we lose heat to

or energy is people. You have splash out and drag out, which I don't like that term. It sounds weird to me and I

Never really heard it. I'm not, I'm not heard it like in a practical application. I've always heard like splash out, you know, it's not a leak. It's just splash out. I've never had anybody say it's not a leak. It's drag out. Cause then I would be like, what are you dragging? You're dragging water out. I get it. It's the water that stuck to you and your clothes and you just.

make you make the water in the pool go away with your body. So.

Why am I bringing this up? Because this all causes you to have to replace the water that was lost. And then you have to rebalance it and it's going to change the temperature of the water. And you're going to have to deal with that. like you got to deal, you've got to constantly rebalance things like salt cells will produce that, that awful scale. The salt cell snow that we all dread.

the warmer temperatures kind of, I don't wanna say cause it, but they definitely play a major contributing factor to that. So for example, if you like, let's say that you are just doing this pool and you've been doing it for a couple, for a while or whatever, and your homeowner shows up and they're like, we're gonna heat the pool. We wanna use the spa, we're gonna heat it, whatever. Soon as they turn that heater on, you're getting flakes in that spa or.

If it's a spillover, it's going into the spa first, you know, you know how this stuff works. But that's, that's something you want to watch out for and be prepared for because then you don't want to get questions. So why is it? What's this in my cell? What's this in my pool? Why is this white, white stuff? Is it going to hurt my kids? You know, so you can try to prevent that from happening by adjusting your alkalinity.

before you know they're gonna start turning the heaters on. If you have the luxury of being able to determine that, which not everybody does. And you can't do it at every pool, but that's okay. So evaporation, I said so again, I was not gonna do that. Evaporation is increased by high water temperature relative to the air temperature. So evaporation is a problem constantly every day all year round. But obviously when the,

air is colder than the pool, it's going to evaporate faster. And then as I said before, as the water evaporates or as people drag it out, people drag it out, this is, you know, my life is turning. You have to replace the water and then you have to rebalance the water. So here's a quick little paragraph that I'm going to quote.

directly from the CPO book just because I thought it was kind of interesting.

The energy loss for one gallon of water evaporation is 8730 British thermal units or BTUs. For example, if a 55,000 gallon pool lost one inch of water due to evaporation, the loss would be 781 gallons. The total BTUs lost would be 781 times 8730

or 6,818,130 BTUs. 55,000 gallons is 458,150 pounds of water, which is also the number of BTUs necessary for a one degree Fahrenheit temperature change.

dividing 6,818,130 by 458,150 represents a BTU loss that is equivalent to a temperature decrease of 15 degrees Fahrenheit for one inch of water loss due to evaporation.

I hope that made sense to everybody because I'm not going to say it again. I barely got through it the first time anyway. So you have evaporation causing most of the energy loss. Now, how do we prevent this? Obviously we add energy to the pool. So let's talk about covers real quick.

I'm not going to, I'm not going to sit and talk about each different type of cover and how to, I'm not doing that. Different show, different episodes. But I did think this part was interesting about the bubble covers. Okay. So we, we all know we have the bubble, the solar blanket, the bubbles thing, the blue one, sometimes they're clear. but apparently try to know this until I was researching for this episode, a bubble cover can apparently that's my quote there.

can apparently absorb around 80 % of the heat energy striking the surface and transfer it to the water.

People will always say it's not going to add heat to the water, it will help keep in the heat that's there, which is apparently not true. It can actually add heat from the sun. Now in order for this to work, you would have to leave the cover on while it's sunny outside, which most people don't. They take the cover off during the day. They put it back on at night, whatever. I don't know. Some people only take it off when they're using the pool.

And that's the way to do it if that's what your intention is. If you're only trying to keep dirt out, I guess do whatever you want. So there you go. Now you have also liquid cover for those of you that have never heard of this. It actually does work. Obviously not as efficiently as, you know, a solar blanket or bubble thing or whatever you want to call it. Not as efficient and it's probably not going to add any heat.

or at least not like not as much as a bubble cover. But it does help minimize the energy loss. I don't have the exact percentage. I don't have the number for you. As I said, it is minimal, but there is a number. So it does help. Now with the liquid covers, just, it works when the water is not disturbed.

That doesn't mean you have to that doesn't mean like you can't have the pump on it will still work with the pump running, but it probably won't work if you have water features, spa spillover. Obviously if people get in the pool, it's going to disperse and you have to add it again. but they, they, do work a little bit and also they help deter birds and ducks and stuff like that because it works as the same way that enzymes do.

It disrupts their waterproofing on their feathers and so they feel the water and then they get wet and they get cold and they don't like it and so they leave. In theory, theoretically, it does work. I've used it before.

And no, doesn't kill the ducks. It doesn't make them sink unless you use a whole shit ton. Okay, there's my swear for the day.

All right, moving on. We have a section on heaters. And as I said, I'm not going to go into details about the different types of heaters. We have gas, we have electric, we have heat exchangers, which are fun. Those are found in the larger aquatic facilities, which borrow

piping, guess they it it borrows the heat from the bathroom like the hot water the water heaters to heat the water to heat the bathroom area stuff like that and so they'll bypass that and feed it into the pool. not gonna go into the details. It's in a CPO book. If you have one you can look it up if you want more info.

or if you really want me to explain it all, let me know in the email that I told you earlier and I will do a deep dive on this as much as I can do a deep dive. So.

So heat exchangers are kind of cool. Heat pumps are a type of heat exchanger. And this is what I have in a lot of my...

lot of the commercial pools that I've done have had a combination of a gas heater and a heat pump. Now if the air outside, if the air temperature is very cold, a heat pump may not be the best solution and may not be the most efficient. I had a I had a commercial pool I was doing a couple of years ago. I don't do it anymore.

And it was the biggest one, the biggest commercial I've ever done, me personally, it was almost 200,000 gallons, not quite. It was like 198 or something like that. And they had four heat pumps.

And the residents kept complaining that the pool is too cold. It's too cold. It's too cold. It's too cold. These were really, really old people. And eventually the HOA president decided that she was just going to turn all of the heaters off, all of the heat pumps off because it wasn't, it just wasn't keeping the water warm enough. And everybody was complaining about it too much.

So she just turned them off. I was like, okay, you're the boss. Makes my job easier. Also less people, cause it's too cold. win-win for me. So that's my experience with commercials and heat pumps. They work, they're efficient, they're fine. But as I said, sometimes they're not. and those can also double as...

you know a chiller we all know they do those things and so you can turn you can essentially convert. If you're if your pool has a pool spa combo. I realize it's not the same thing I realize that. But this is what people have been doing.

and they've been using their spas as a cold plunge and they turn on the chiller instead of the heater. Which is fun. For them.

I used to have this pool that would do that. They would turn their chiller on and then they would leave it on and then they would leave their pool in spa mode. And so I would get there and the spa would be completely half empty because they let it sit at 48 degrees for a week, you know, and it's 78 degrees outside and the

the equipment's all sweaty from being cold. man, it was the worst. It was such a problem. And you you turn it back into pool mode and now you got to fill the pool because the spa was half empty because it all evaporated away. so frustrating. I wish people would just not touch their stuff. Just don't touch it. So anyway, it's my pool, not yours. Just kidding. Then you have your solar panels, which are fine.

I've actually held my hand in front of a return and it was coming out warm. So they do work. They tend to leak a lot. They tend to have leaks just spraying out all over the place. So I rarely come across solar systems that actually work. Rarely. Most of the time they're bypassed or cut. Nobody uses them.

for the most part. So the last two benefits that you get from cold water, because that's actually what this episode was about. I don't know if I mentioned that in the beginning or not. You get less potential for algae blooms.

Obviously, since the water is cold and algae prefers warm water, you've taken away one of its conditions for being able to bloom.

And then on that note, you also are able to use less chemicals than normal. Since the water is already kind of corrosive, could maybe you don't need as much acid and maybe you don't need as much chlorine. Me personally, I just kind of use the same amounts. I don't usually like to lower the amount that I'm using. I'm not saying that

Like I disagree with doing that or anything. It's just, I don't know. I don't like the idea of a transition. I don't like the idea of like, I have to do this because it's this time of year and I have to do this because it's the, I'd rather just do the same thing all the time. So, you know, I don't know. Maybe I'm sure there's going to be people that disagree with me, but, and I'm not saying don't, I'm not saying don't change your routine. If you don't need to use as many chemicals, don't use as many chemicals.

don't use as much. It just makes it easier for me when I don't have to sit and like go through figuring things out like this pool, it's winter time I only I only need this much instead I'm just gonna add the same amount.

Everybody should tell me how mad that statement made them. It's okay though. I'm used to it now. So anyway, that's, that's all I got for today. I know this is real, real short and I hope it wasn't too awkward with me just not having a cohost to banter with and not having someone interrupt me and try to derail my thought process. Anyway.

She'll be back, don't worry about it. She'll be back. But yeah, that's it. That's all I got for now. So I hope everybody has a great holiday weekend that is coming up. I think when this comes out, Thanksgiving will be at the end of the week. It's my birthday. It's my birthday that's the holiday coming up. So happy holidays to me.

And I hope you guys all have a great Thanksgiving. I'm just kidding, of course. And yeah, let me know how you feel about the episode you just listened to. Thank you for listening to it. If you have any ideas, let me know. I don't know. Maybe if you want to jump on and be a cohost for a day, let me know. Message me. You can,

Email me as I said, and I guess that's it. I'm just kind of rambling now. thanks to our sponsors, my sponsor for today, Revved Up Apparel. You guys are amazing. And that's it. Bye.