Why Is My Pool Water Tinted? Joe Laurino Explains

A pool can look perfect on Friday, then turn an eerie green tint right after you shock it and suddenly everyone swears it’s algae. We’ve seen it on routes and heard it from homeowners: clear walls, no visible growth, but the water has a strange color cast that shows up fast. The fix starts with stopping the guesswork and running a simple, chemistry-driven test that tells you what you’re actually fighting. 

We’re joined by Joe  Laurino of Culator Products to unpack the real causes of tinted pool water, including organic haze from tannins and humic acid after a fresh fill, and the metal-driven color shifts that appear when chlorine oxidizes copper or iron. Joe explains a practical field method: add ascorbic acid and watch what happens. If the tint snaps to crystal clear, you’ve likely confirmed metals and can move to the right next steps, including a sequestering agent and a metal remover like CuLator 4.0, instead of endlessly shocking and brushing. 

We also get into the “purple dust” many techs now find in skimmers and cleaner hoses. Joe breaks down why it forms when copper meets cyanurate, how trichlor tablets push cyanuric acid (CYA) higher over time, and why high stabilizer levels can weaken chlorine and create a cycle of relying on copper products. Then we tackle the curveball: iron bacteria. If a stain disappears with ascorbic acid but returns within a day or two to the exact same spot, that’s a huge clue, and Joe shares how to confirm it and the EPA-backed treatment approach using copper algaecide and high chlorine. 

If you service pools or manage your own, you’ll leave with clearer diagnostics, fewer wasted chemicals, and a smarter plan for green pool water that isn’t algae. Subscribe, share this with a pool pro who’s chasing “mystery tint,” and leave a review with the strangest water color you’ve ever seen.

We break down why pool water can turn green or tinted right after shocking even when the pool is spotless, and how to prove whether you’re facing metals or organics in minutes. Joe Loreno from Creative Products explains purple dusting, high stabilizer side effects, and the iron bacteria problem that fools even experienced techs.
• using ascorbic acid as a fast metals test for green or brown tinted water
• distinguishing stained water from a stained wall or floor
• adding sequestering agent and using CuLator 4.0 after metals are confirmed
• spotting organic tint from tannins and humic acid after fresh fills
• explaining purple dust as copper plus cyanurate from elevated CYA
• why high cyanuric acid weakens chlorine and pushes copper product overuse
• identifying iron bacteria by rapid stain return and same-spot reappearance
• using the toilet tank orange slime check to confirm likely iron bacteria
• treating iron bacteria with copper algaicide and superchlorination
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Transcript

Welcome And What We’re Solving

SPEAKER_01 1:02

And welcome to the Fest of the Fool Way Podcast Show. In this episode, I'll be joined by Joe Loreno of Creative Products. And these are the stylator products that you'll use out there on your pool route that helps eliminate metals in the pool. And in this episode, we're going to talk about the tinted watercolor, something that you may run into out there on your pool route. 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 get a lot of questions about this from people and from pool guys, and they'll get to a pool, they'll balance the water, and all of a sudden they'll see that or they'll shock the pool. One of them shocked the pool right before a party over the weekend, and then the water had this green tint to it. Can you go over some of the reasons why you would have, you know, I think some people think it's algae in the pool. They may think that they're looking at the sun hitting the pool and then the algae reflecting off of it, but then they realize that there's nothing on the walls and they brush it. It's just a green tint to the water, or maybe a different color tint. And so what are those color, the tinted water indicate?

SPEAKER_00 2:20

Well, it it indicates again the a stained water is to me and to a chemist just like a

Tinted Water Versus Algae

SPEAKER_00 2:29

stained surface, right? It just hasn't oxidized yet, or it won't oxidize depending upon what it is. So if you if you fill your pool and it's a fresh fill, you you'll often get what are called tannins in the water, humic acid and other materials. And that tends to give a haze to the to that water. And that's really organic in nature. So sometimes when you shock the pool, you get the reaction with the chlorine and that material. And what you need to do is to put additional additional chlorine in that water. But again, you want to eliminate whether or not it's metal, it's inorganic. So do the same thing. Dump in ascorbic acid. The ascorbic acid, if that if that pool is green or brown and you put in a pound of ascorbic acid, and that pool turns crystal clear, that tells you that it is a metal stain. And therefore, treat it just like you would a regular metal stain. You've basically taken the particles, the metal particles that have oxidized that haven't played it out yet, and that's what's caused the color, especially when you just put in chlorine. That's kind of a giveaway that you've oxidized what's in there. So you want to put in ascorbic acid, you want to put in sequestering agent, and you want to put in a Culator 4.0. It's basically stained water and not a stained wall. If you put in ascorbic acid and nothing happens, then it's usually organic in nature. And that's when you want to flock and filter.

SPEAKER_01 4:02

Got it. That makes perfect sense. And so any kind of tinted water means that there's something, I mean, doesn't actually mean that there's metals in there, but you have to kind of eliminate that with the ascorbic acid just to make sure. Correct. And so I mean I know you mentioned in the other recording about the purple dusting, which is becoming more and more common as people are using copper products in their pool, algecize and other copper, they introduce copper into the water. And then because of you, because of the overuse of the triflor tablets in the industry, the purple dusting has become very common. You'll see it everywhere in the cleaner hoses, you'll see it on in the skimmer, you know, like on the water line in the skimmer, and on the skimmer basket. Depending on how bad it is, it'll be very noticeable. And you want to go over what that purple dust actually is and kind of how to get rid of it?

SPEAKER_00 4:55

Sure. The purple dust is composed of two things. The first one is copper, all right, which is coming from the algebra

Purple Dust From Copper And Stabilizer

SPEAKER_00 5:22

the copper ionizers, or if you happen to let your pH go down too low and you have a a gas-fired water heater, you may have blown out your heater core and put copper in your pool. But that copper is coming from from one of those sources. And as you mentioned, the other part of that molecule or that that purple dust, cyanurate, which is coming from this, from the from what is called the stabilizer, the chlorine stabilizer, which is half of the weight of the trichlor tablet. So it's really an elevated uh concentration of both the both the the stabilizer level and also the copper level that's causing that purple dust to form.

SPEAKER_01 6:11

Yeah, and so I know that the the common thinking is that you have to drain the pool, drain most of the water out to lower the cyaneric acid level. But is there a way to remove the staining with a C later product in the meantime?

SPEAKER_00 6:25

Sure. I mean, obviously if you were to remove the copper component from the pool, the the purple color will will go away. But again, that only addresses half of your problem. The other half of the problem is the the elevated stabilizer, which is causing the chlorine not to work as well, which is probably causing things like algae to grow, which is why you're putting copper algae side in the pool in the first place. So you really want to solve both of those issues, and and until we find a way to take to take cyanuric acid out of the pool, the best thing to do is to is to drain the pool. Or to not I don't want to say completely drain, but to take some of the water out and replace with fresh water so that you you can get the levels of things down.

SPEAKER_01 7:13

Yeah, and I've I was on your site looking at some of your material and I saw that you had a link for iron bacteria. Um can you explain what that actually is for the to the listeners?

SPEAKER_00 7:24

It is a harmless bacteria that is found in well water. And you may say, well, I don't use wells to fill my pool or to get my water because it's from the city, but the city may use wells. So they may drill wells and get and and obtain groundwater that they then treat. And what happens is that this is a normal bacteria that lives down in the in the wells, and it tends to clog the well head over time, and the the city's response to it or the the water district's response is to superchlorinate. They dump chlorine down the well, and that frees up the pipe, and then it clogs again, and it basically becomes resistant to

Iron Bacteria That Mimics Stains

SPEAKER_00 8:07

the chlorine. What they do then is they just drill another well hole and plug that well hole up, but the bad, but but but the iron bacteria is still there. So it's a problem that's always been there, but because they've been basically superchlorinating these wells, it tends to create kind of this really vigorous bacteria that once it gets into your pool and it gets on the surface of that pool, it tends to become a problem for you to get rid of because it shows up like an iron stain. And you can kind of tell if you have this when people call and they don't know is it iron bacteria, I tell them to go into their bathroom and take the the back of the toilet tank off, you know, the top of the toilet tank. And if they see this kind of orangey slime material around the water line, that's actually the bacteria, the iron bacteria. So if you have it in your house and you use that to fill your pool, chances are you've got that in the pool.

SPEAKER_01 9:06

Huh. So how do you how do you get it?

SPEAKER_00 9:07

Is it not it's not a metal per se then, right? No, it and it's it's one of those, you know, basically what I said was 99% of the stain, stain removal cases are really easy. This falls into the 1%, right? And this is what happens is that it looks just like a metal stain. You you put ascorbic acid on it and it goes away, right? So you think, okay, well, that's gotta be iron. What happens is that the bacteria incorporates the iron inside the bacterial cell. And there are two forms of iron. One is the orange color that we're used to, kind of that rust color, and the other form is actually colorless. So it doesn't show up as any color at all. Well, what happens is that that the ascorbic acid converts the iron in the bacteria from that orange color to that colorless color. So it's gone away, and as soon as you put chlorine back in the pool, the stain comes back. So there's two things that you look for here. So you're gonna you're gonna think it's a metal stain and you're gonna treat it. And remember, I said that when you treat the metal stain, the sequestering agent should last for 30 days. Well, if this stain comes back in a day or two, that means that it's gonna be iron bacteria because what happens is as soon as you take away the ascorbic acid, and you've got that cloudiness gone because the chlorine has has reacted with all of that ascorbic acid, and you have a little bit of chlorine left in the pool. Well, there's no more ascorbic acid. So that iron in that bacteria turns from colorless to orange, the stain's back. But but so the stain was caused by the organic bacteria, not by the iron going into the water, because it never left and went into the water. It stayed there. The other thing that you'll notice is that the stain comes back to the exact same spot. Well, you can imagine that if you took a stain off the pool wall or floor and you and and you dissolve that metal into that water and it's freely floating around in your you know 20,000 gallon pool, the odds of that metal going back to that exact same location and staying in the pool is zero, right? So if the stain comes back to the same area the day after you took it off, it's it's 99.999% chance that it's that it's iron bacteria. And to solve the problem, because that's you're not, you can see that's your next question, you treat it like an algae stain. You use copper algaicide, and you will basically superchlorinate the pool after that, and that will get rid of that uh of that iron bacteria. That's the EPA method of actually getting rid of the bacteria is copper algicide and high levels of chlorine. And how common is that in in the industry? Uh five or so years ago, it was not not very common at all. But as cities and towns have gone more to well water and and more more to groundwater to mix with whatever other sources of water they may have. And as they've treated this by basically superchlorinating the well heads, it's become more and more of a problem. So it's it's more common now than it ever was, and but it's easy to figure out when the stain stain removal process fails, you have to trust the chemistry and then say it's probably iron bacteria, and then treat it, and then it will go away.

SPEAKER_01 12:50

Interesting. Yeah, something that um a lot of things are changing in the industry as things happen in the municipalities, and I think that's something that getting educated on this is really important for a lot of the the homeowners and pool professionals out there. So great information on your site, by the way, too. And you want to throw your website out there again for the listeners?

SPEAKER_00 13:11

Yes, it's www.seulater. That's c ula.com.

SPEAKER_01 13:18

Again, the website is seeulater.com. If you want to get more information about the topics we discussed here and also see their articles and photos, you can definitely go to their website. And from their website, you can definitely email them or call them directly to get more help with the products you're gonna need to reverse any kind of metal screening in your pool or pool that you're servicing. And if you're looking for more podcasts, you can find those by going to my website, swingforlearning.com. On the banner, there's a podcast icon. Click on that, and over 1900 podcasts will be available for you to listen to at your leisure. And if you're interested in the coaching program that I offer, you can learn more at poolguycoaching.com. Have a great rest of your week and God bless.