Terry and Eric discuss different types of algaecides and the byproducts they leave behind. Spoiler alert, chlorine conflicts with all of them.
00:00 - Introduction
01:03 - Types of algaecides
01:52 - Copper sulfate
04:54 - Quat and Polyquat (quaternary ammonia)
08:11 - Enzymes conflict with polyquat algaecide too
09:53 - Sodium bromide
13:35 - Mineral systems and ionized metals
16:09 - Ammonium sulfate and Dimethyl ammonium chloride
19:14 - Polymers
20:13 - Wrap up
------------------------------------
Connect with Orenda Technologies
Website: https://www.orendatech.com
Help Center: https://ask.orendatech.com
Blog: https://blog.orendatech.com
YouTube: https://www.youtube.com/user/OrendaTechnologies
Facebook: https://www.facebook.com/orendatech/
Instagram: https://www.instagram.com/orendatechnologies/
Swim Across America | Team Orenda: https://www.swimacrossamerica.org/goto/orenda
122. Chemical Conflicts | Algaecides
===
[00:00:00] Eric Knight: Continuing on with our multi part series on chemical conflicts This is episode 122 of the Rule Your Pool podcast, I'm your host, Eric Knight, and with me as becoming more regularly, Terry Arko. Thank you for being back on the show.
[00:00:14] Terry Arko: Hey, thanks, Eric. Glad to be here.
[00:00:16] Eric Knight: Yeah, I'm glad to have you. And this is really not my area of expertise. You were on the last episode, but as we both know, due to some technical difficulties, I had to re-record it, unfortunately. But we got you now. I think you can really add a lot of value because I don't know as much about these conflicts as you do.
[00:00:32] So in this episode, Terry and I are going to be talking about algaecides. Algaecides are always, if they're not named chlorine, a contributor to chlorine demand. Terry, is that your experience as well?
[00:00:45] Terry Arko: Absolutely. Any type of chemical you use that puts something which chlorine has an affinity to oxidize is going to create more chlorine demand,
[00:00:53] Eric Knight: Right. We have a few more episodes after this with you. So let's get right to it. Episode one 22. Let's go.
Types of algaecides
---
[00:01:03] Eric Knight: I had a call from a customer, I think it was last week, shortly after the last episode came out. And he called me and said, Hey man, I can't hold chlorine for a week. And you made mention in your episode that chlorine will conflict with things in the water. So in this episode, what I want to break down is the multiple different things that chlorine is going to conflict with. Because all of these things are going to contribute to the chlorine demand.
[00:01:42] Rapid fire, Terry, I want to go through the different types of active ingredients that you might find in an algaecide, and let's just talk about what happens when you put that in a water. Sound good?
[00:01:51] Terry Arko: Yeah.
Copper sulfate
---
[00:01:52] Eric Knight: Okay. Copper. Copper sulfate is the most common ingredient I've seen. What happens when that goes in the water?
[00:01:58] Terry Arko: Commonly what's used is copper sulfate pentahydrate. Right off the bat, that's going to create some chlorine demand and copper. When you have copper present in the water, that's one of the first things that chlorine is going to want to go after. Any form of metal, when you add chlorine to the water the first thing it's going to want to oxidize is those metals that are in the water.
[00:02:21] Eric Knight: Lowest energy, highest affinity for those metals.
[00:02:24] Terry Arko: And the thing about certain products like that, these copper algaecides and so forth, is that they're in a chelated form. So initially, I would say there's not going to be an interference there. But what happens is, over a period of time, from excessive oxidation, which is going to be happening all the time, every time you're adding chlorine. And contact with the water, which is hydrolysis. Those chelators begin to break down. And over a period of time that chelator is going to release copper.
[00:02:54] Which is basically going to be just be in the free form of copper, which is what chlorine is going to want to go after and oxidize. So if you're using copper algaecides, uh, the thing to keep in mind with that is, yeah, initially you may not have a problem. But as you continually use those products and they build up, over time, the chelation that you've had in the pool for a while is going to get oxidized away. It's going to hydrolyze. And it's going to release that copper into a free form.
[00:03:23] Which, based on where your pH goes, can lead to a staining issue. Which chlorine is going to want to oxidize at that point as well.
[00:03:30] Eric Knight: Do you know if the chelating agent in those copper algaecides is EDTA?
[00:03:36] Terry Arko: Yes.
[00:03:37] Eric Knight: Okay. That's why it can break down.
[00:03:38] Terry Arko: Right. Exactly. It will, it will break down over time.
[00:03:41] Eric Knight: Well, we've seen it for sure. SC-1000 is not EDTA. So that's why I asked.
[00:03:45] Terry Arko: Well, I, I worked formerly for a company that sold a copper based algaecide. And it was an EDTA chelated form of copper. And it was a low percentage, so we didn't see a lot of issues, but I can tell you that there were issues that would come up. Especially with people who used it consistently.
[00:04:04] Eric Knight: It's an effective product. I think all of these things are effective at what they claim to do, especially if they have EPA registration. And by the way, if you're using a product that does not have an EPA registration and they're claiming to kill algae.
[00:04:14] Terry Arko: No.
[00:04:15] Eric Knight: Don't use that product because that's a violation of federal law. You have to get EPA certified to be able to make those sorts of claims on bottles. The point is, it's not that the chemicals that we're mentioning in this episode don't work. No, they do work. They wouldn't sell if they didn't work.
[00:04:30] Terry Arko: That's correct.
[00:04:31] Eric Knight: It's that they leave behind byproducts that conflict with chlorine, and that's what we're talking about. If we go back to Orenda's philosophy, it's proactive pool care, with no chemical conflicts, and no long-term byproducts left behind. Algaecides violate the last two of those three. Well, actually all three, really. They're not really proactive. Some could be, but generally speaking, you're going to add an algaecide when you have an algae problem.
Quat and Polyquat (quaternary ammonia)
---
[00:04:54] Eric Knight: Some people will put in the next type of algaecide as a preventative. The 30-day, the 60-day, the 90-day algaecide. What are the active ingredients in those kind of products, Terry?
[00:05:05] Terry Arko: Oh, so those would be, uh, either quaternary ammonias, or they would be polyquaternary ammonia.
[00:05:10] Eric Knight: What's the difference between those two?
[00:05:13] Terry Arko: When you add a quaternary ammonia to water that's got chlorine in it, uh, the first thing you're going to do is you're going to create ammonium ions. Those ammonium ions are going to convert to monochloramines very quickly. And those monochloramines are going to convert to dichloramine very quickly. And that's the killing process there to the algae. Is that those chloramines are slower. They tend to penetrate more into the algae and that's what causes the algae to die off.
[00:05:39] However, you're also consuming a lot of chlorine in doing that. Then the dichloramines basically those should, uh, hopefully leave the pool in the form of a gas. But that doesn't always happen. You can get a buildup of chloramines.
[00:05:55] Eric Knight: That would be trichloramine or nitrogen trichloride. That's the air quality issue on indoor pools. So when you're saying chloramines, I'm thinking, man, combined chlorine is such a huge problem for commercial pools, especially. And for the listeners out there, if you ever test a difference between your total chlorine and your free chlorine, that difference is called combined chlorine. And that's chloramines.
[00:06:15] Ideally, that number is zero. You don't want that because chlorine is combining with nitrogen compounds. And if you have that, again, we've talked about this in previous episodes and blogs, the only question you need to be asking is where did the nitrogen come from?
[00:06:28] In this case, it came from the algaecide. Because QUAT, Q U A T, is short for quaternary ammonia. Now polyquat has polymers in it as well. Is that correct?
[00:06:42] Terry Arko: Yes.
[00:06:42] Eric Knight: Okay. So elaborate on that.
[00:06:44] Terry Arko: Polyquat basically is taking a quaternary ammonia and they're attaching a polyacrylamide to that chain, if you will. So it's termed as a polyquat. The main reason for the polymer is that polymers as we know, basically, and we'll talk about this in the in our polymer episode. But just real briefly, it creates a long chain. A lot of carbon atoms on that chain. Those carbon atoms are very strongly charged and they tend to go towards negative charge material and they form flocs and that sort of thing.
[00:07:15] So they bind things to them very quickly and very easily. In the sense of the algaecide, the polyquat algaecide, uh, the polymer is going to stick more to the algae and especially if you have free floating algae, it's going to grab that algae or it's going to form a floc of that algae to the quaternary ammonia to kind of, I guess, get a better killing agent, uh, from that sense.
[00:07:38] And also any dead algae that's floating around or whatever, the idea is the polymer is going to floc that and that's going to go to the filter and be removed better by the filter. That's kind of the idea there.
[00:07:49] Eric Knight: Interesting. And I know that this allows it to have more staying power because that's the 30, the 60, the 90 day...
[00:07:56] Terry Arko: Correct.
[00:07:56] Eric Knight: ...algaecide products are typically polyquat. Now, not only will chlorine conflict with both the poly and the quaternary ammonia. Chlorine will attack both of those things, and that increases your chlorine demand. Uh, some more than others, but generally speaking it's going to increase chlorine demand.
Enzymes conflict with polyquat algaecide too
---
[00:08:11] Eric Knight: That's not the only product that conflicts with this. Our enzymes do too. We have seen people add polyquat well, I should say, I haven't personally seen it, I've seen a video shortly after somebody poured the product in and he texted me and said, Why is this foaming like crazy? And he put polyquat algaecide in a CV600 pool.
[00:08:30] He put it in an Arenda pool. And, There was no algae in the pool. It was done to be preventative going into the fall and it bubble bathed like crazy. Why did that happen?
[00:08:40] Terry Arko: Well, there could be various reasons. I would suspect the number one reason if you use a quaternary ammonia and I believe on many labels it even says uh, Quaternary ammonia will cause foaming.
[00:08:52] Uh, and a polyquat, so basically you've got the polymer, which is a hydrocarbon form or a petroleum based polyacrylamide attached to the quaternary. And what do enzymes do? Enzymes digest oil. So the enzymes, I'm sure go after the oil in that polymer. And in a sense, what happens is it becomes De polymerized, and so now you've got quaternary ammonia, straight quaternary ammonia in there, which is going to foam. I would suspect there's probably other reactions that are going on possibly with, uh, surfactants, uh, that may be in either one of those. And that can cause foaming as well.
[00:09:31] Eric Knight: Yeah, that's our theory. Enzymes bubble when you first put them in anyway, I just figured it was going after something organic. And that's when we figured out polyquat is not compatible with CV600 or CV700 or CE-Clarifier.
[00:09:43] It's not compatible with our enzyme. So if you are having an Orenda pool, please don't put a polyquat algaecide in there. You shouldn't need it in the first place, but it's going to foam.
Sodium bromide
---
[00:09:53] Eric Knight: Alright, moving on. Sodium bromide. I don't want to dwell on this because you and I did a very detailed episode on bromine in the past one. I think I can take this on a little bit and then just fill in the gaps.
[00:10:03] Sodium bromide is a salt of bromine. Table salt is sodium chloride. But this is sodium bromide. And the reason this consumes chlorine so much is because chlorine has an affinity for oxidizing it into hypobromous acid, which is the killing form of bromine, which cannot be stabilized to protect it against sunlight degradation.
[00:10:24] So it could be an effective oxidizer. It could be an effective algaecide in the short term, but it's going to get burned out very quickly by direct sunlight. Therefore, it's this vicious cycle, never ending cycle, by the way, of chlorine attacking that bromide ion and recharging the bromine cycle. Did I miss anything in that?
[00:10:45] Terry Arko: I know we covered this, but just to consider that even in bromine tablets that are used for spas or hot tubs, you've got B C D M H, those tablets. That's bromo-chloro-dimethyl-hydantoin.
[00:10:57] So why is the chlorine in there? Well, the chlorine is in there to act as an oxidizer because it oxidizes the sodium bromide into active hypobromous acid, which is the killing agent. And by the way, there's lots of research and lots of data where they claim that, uh, hypobromous acid is a better algae killer than just regular hypochlorous acid. That it kills better.
[00:11:18] I'm just saying there's papers out there, not saying whether they're correct or not, I'm just saying there's data that makes those statements. And I think based on the data that makes those statements, that's what launched these chemical lines to where they're saying Bromine is a better way to kill algae than chlorine. So here's these sodium bromide based products now.
[00:11:35] Eric Knight: Do you buy that?
[00:11:36] Terry Arko: I don't buy it. I still
[00:11:37] Eric Knight: I don't either.
[00:11:38] Terry Arko: I think chlorine used correctly is the best algaecide anybody can have.
[00:11:43] Eric Knight: I agree. Bob Lowry said that. Chlorine is the best algaecide or free chlorine. I should say it doesn't matter what type of chlorine you put in the pool. HOCl is what he was referring to. I agree with that.
[00:11:53] Terry Arko: And we could spend the whole episode on that and about proper free chlorine and how proper free chlorine can do a lot and go towards a lot.
[00:12:00] Eric Knight: Dang, Terry, you're making me write down all these episode ideas. You know, I have customers and listeners that suggest episodes too, and you keep coming up with some good ideas. So maybe we will do that. Let's keep moving in the interest of time though.
[00:12:11] Terry Arko: The thing with the bromine is that, exactly as you said, so they've come out with these sodium bromide based algaecides and products you put in there. The problem, though, as we stressed in that episode, which everyone should listen to on bromine, is that that hypobromous acid is going to, eventually once it's done what it It needs to do, it's going to convert back to that sodium bromide salt.
[00:12:34] That sodium bromide salt is never going to leave the pool unless you drain or get an incredible amount of splash out, something like that. So it's always there. Every time you add chlorine to that pool, the first thing the chlorine is going to want to do, it's going to have the affinity to go after that sodium bromide, oxidize that sodium bromide.
[00:12:52] Well, now that consumes. your chlorine that you're putting in the pool to deal with bacteria and sanitize and so forth. So that's the issue there. You've got to really be careful on using those, those types of products.
[00:13:04] Eric Knight: You know, we're talking about things that chlorine really likes to oxidize. Now, it's very hard for chlorine to get rid of something like sunscreen or makeup or deodorant.
[00:13:12] But it's very easy for it to get rid of a metal. It's very easy for it to oxidize because the energy required to oxidize iron or copper is much lower than it is for a complex hydrocarbon like sunscreen. Am I understanding that correct?
[00:13:27] Terry Arko: Absolutely.
[00:13:27] Eric Knight: That same thing applies to sodium bromide. Because the bromide ion is very easy for chlorine to attack and that's why it has an affinity for it.
Mineral systems and ionized metals
---
[00:13:35] Eric Knight: So continuing on with things that chlorine likes to attack, let's talk about the other metals that we have. So we talked about copper sulfate or copper sulfate pentahydrate. Now let's talk about mineral systems. These are supplemental products that can be put in skimmer baskets or strainer baskets. They're quite popular and they are effective against algae. These are things like silver chloride, coppers, or even ionized copper, which is more of a residential system that you might find at a retail store.
[00:14:04] It's a specialty system that supposedly you don't need chlorine and they just electrify copper and they put copper into the water. What do these conflict with, Terry?
[00:14:13] Terry Arko: Well again, chlorine demand. The idea of this whole thing with the silvers and the zincs and the different things that are being added through these ionizers comes from different industries, not necessarily from the pool industry. But when someone's going to say, Hey, this is all you need. First in a pool, I'm going to say, you're never going to get away from needing chlorine, no matter what you're using. So if you have ionizer systems
[00:14:35] Eric Knight: or residual sanitizer, yeah.
[00:14:37] Terry Arko: You still that have to have residual sanitizer.
[00:14:39] If you buy into something where you get an ionizer system and they're telling you zero chlorine, or you don't need chlorine anymore, um, you should run from that. Because that's incorrect and that's going to lead to a lot of problems.
[00:14:51] But yeah, chlorine demand. The same thing applies. I think in the short term, initially, when these products are added, they have a benefit. However, the issue becomes when you have these say the copper or the silver, whatever it is, that begins to build up in the pool. And chlorine is going to oxidize those. Uh, hydrolysis is going to do its job.
[00:15:19] And you're going to have these spent metal ions now, uh, that are going to build up in the pool and that's where chlorine is really going to get consumed. Because chlorine is going to just go after those like, boom, right away.
[00:15:32] Um, that's the same thing as if you have copper in your source water, or iron, or any type of metal, manganese or whatever, and you're filling your pool. Again, the first thing that's going to happen when you add chlorine is it's going to get consumed oxidizing those source metals. And it'll do the same thing when you have an ionizer in there.
[00:15:51] Eric Knight: And eventually, it passes a threshold, the pH gets high enough, you get a stain. So, those are metal issues. We are not a company that dwells on metal issues, although we do get a lot of calls about stains. That's not really our wheelhouse. Maybe in the future, but for right now, that's really not our specialty. But we do get a lot of questions.
Ammonium sulfate and Dimethyl Ammonium Chloride
---
[00:16:09] Eric Knight: So let's wrap the algaecides group with ammonia based algaecides. Now we talked about quaternary ammonia, and I would lump that in with ammonia based, but there's two others that if you look at the active ingredients, I have seen ammonium sulfate and dimethyl ammonium chloride.
[00:16:27] I think it's pretty safe to say chlorine is going to combine with these because it is nitrogen. Is that correct?
[00:16:32] Terry Arko: Yeah, and that's actually, the manufacturers, they would say that that's how the product is supposed to work in a sense. Okay, so ammonium salts, for example, which that's a dry powder material. So you're pouring a certain amount of an ammonium salt into a pool that's mucked up with algae. Uh, it looks like a lake. Uh, and then you're going to add chlorine. Liquid chlorine, it might be one or two gallons. If you're doing Cal Hypo, it would be one to two pounds. And the concept there is you're oxidizing that ammonium immediately. So you're creating that ammonium from the ammonia salts.
[00:17:10] However, you'll notice in those products, they tell you not to just add the chlorine once right after you add the product. But then by the next day or so, you've got to come back and do a super chlorinate again. Why? Well, that super chlorinate is to hopefully deal with or break up the chloramines that you've created to do the kill in the first place.
[00:17:31] And that's a huge consumption of chlorine right there. And that's where you can get problems down the line. Again, I'm going to say in the short term, these products tend to work. I worked for a company we sold ammonium salts and they were effective and they worked. Um, but I will say one of the things we dealt with, in many cases, was people who had gone through this system and done this system and then they're having a hard time getting back to where they can create a chlorine residual after the use of these.
[00:18:01] And a lot of that just has to do with what's been left behind and that it's consuming the chlorine.
[00:18:06] Eric Knight: Right. Combined chlorine, chloramines, all that stuff.
[00:18:08] Terry Arko: Right.
[00:18:08] Eric Knight: We know, again, I come from the commercial pool world as a swimmer who got really sick from breathing this stuff in when it off gases. So for me, when I see combined chlorine, That's a red flag immediately. And inorganic ammonia creates monochloramine, dichloramine and trichloramine, but dimethyl ammonium chloride is actually organic ammonia and that is a lot more complex. It takes more chlorine to get this stuff oxidized. It takes more for it to get out So it's just going to increase the chlorine demand even more.
[00:18:36] However, It is a very popular cleaning agent. It is commonly used on decks, to clean floors and bathrooms, and it's used in your house. If you have cleaning products, I won't say brands, but very popular cleaning products, look at the active ingredient. It's probably either sodium hypochlorite, chlorine, or dimethyl ammonium chloride or dimethyl benzyl ammonium chloride or something like that.
[00:18:59] Terry Arko: Dimethyl benzyl ammonium chloride, which is a really common ingredient and a lot of like Lysol and those kinds of things have it. And I'll also say if you use any kind of a purge this might be more so for spas, But there are pool purge products out there as well.
Polymers
---
[00:19:14] Eric Knight: So that leads us to the last thing that chlorine might conflict with, at least on this list. I'm sure there are other things... is polymers. You know, we mentioned it in the previous episode, which of course I couldn't use your audio. So I guess we need to restate it. Chlorine will also conflict with polymers in the water.
[00:19:31] So polymeric clarifiers was one example that you gave, which I didn't know. I actually learned that and I'd like to touch on that because if you have a polymer clarifier, is that the same kind of polymer that you're going to have in polyquat algaecide?
[00:19:45] Terry Arko: Yes, it's the same, if it is a synthetic clarifier or polymer. And what I mean by synthetic, it means that the polymer is a polyacrylamide. Polyglycol, something like that. Um, many of them use those, or they just use what's known as polyacrylamides. That means they were synthetically created. They weren't natural polymers like chitosan. And also they're petroleum based. Of course, chlorine is going to go after all those things.
[00:20:10] Eric Knight: And so are enzymes.
[00:20:11] Terry Arko: And enzymes as well.
Wrap up
---
[00:20:13] Eric Knight: Right on. Okay. Well, I think that's it for this episode. So when we talk about algaecides on this show, and in our blog, it's not that we're anti algaecide because they don't work. I'm going to restate it. We don't like algaecides because they leave behind long term byproducts that conflict. They conflict with chlorine, and they're not even as effective at killing algae as HOCl. Hypochlorous acid, good old chlorine. Free chlorine is the best algaecide you can have. And that was not just us saying that, it seems to be pretty well understood.
[00:20:46] I was looking at some medical journals and I found out, are white blood cells create hypochlorous acid when they're trying to kill germs. And maybe it was you that gave me that hint and I started looking at it. You're nodding, but we're not on camera. So, HOCl is the most known, most trusted disinfectant in the world.
[00:21:04] Is that a safe statement to make?
[00:21:05] Terry Arko: That is a very safe statement, yeah.
[00:21:07] Eric Knight: Okay, so. If you want to avoid chemical conflicts, if you want to be proactive, if you want to rule your pool, try to avoid these things. It's very easy to prevent these chemical conflicts. Simply don't put the products in your pool.
[00:21:22] If you feel that you need them, just understand that there are consequences to doing that and you're going to have to deal with the baggage. That's all we're saying. Terry, anything else you want to add to this episode?
[00:21:32] Terry Arko: I think where people get into trouble, even when they do use these products, they're using them as a replacement to good free chlorine in the pool. And when you start off there, you're just going to wind up in trouble.
[00:21:48] Eric Knight: Fair enough. This has been episode 122 of the rule your pool podcast. Terry, thank you again for being on this episode and we will see you on the next episode when we talk about alternative sanitizers. Thanks everyone.