In the swimming pool and spa industry, calcium is treated like it's a four-letter word. But if managed correctly, calcium hardness can be your best friend. So, what is calcium hardness anyway? According to the Rule Your Pool Guys, it’s the concentration of calcium in your pool, and the most stable factor of the LSI. Calcium is so stable, that Orenda bases their LSI management strategy around it. In this episode, Eric and Jarred discuss the benefits of calcium hardness, some misconceptions surrounding calcium, calcium hardness increasers, and how to lower calcium hardness in a pool. They also get into the weeds on the Orenda Academy exclusive hat, calcium testing issues, calcite crystals, and a whole lot more.
01:01 - Episode Takeaways
03:12 - What does calcium hardness do for a pool?
05:58 - Calcium Hardness in Desert Climates
09:35 - Calcium Hardness Testing
13:56 - How Calcium Hardness Affects Scale
15:58 - How Much Calcium Does Calcium Hypochlorite Add?
18:07 - Advantages of High Calcium Hardness
20:35 - Calcite Crystals
24:43 - How To Lower Calcium Hardness
27:33 - How To Increase Calcium Hardness
33:54 - How Often Should You Test Calcium Hardness
Resources
Connect with Orenda Technologies
6. The LSI | Calcium Hardness
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[00:00:00] Eric Knight: Hey everybody. Welcome back to episode six of the Rule Your Pool podcast. I'm your host, Eric Knight, and with me as usual is my cohost, Jarred Morgan. Jarred, thanks for being here.
[00:00:11] Jarred Morgan: Howdy. If you are, obviously, if you're watching great. If you're not watching, I'm just sporting a new hat we have here. Everybody can take a look.
[00:00:17] Eric Knight: Yeah, the Orenda academy, exclusive hat. I have mine. Mine's flat billed. I'm not wearing it because, well, I look silly when I wear a flat billed hat. But they are popular and you can get your hat by passing Orenda Academy, four pillars. We will personally give you a hat. So thanks for that shameless plug.
[00:00:35] Jarred Morgan: I'm happy to give you a curve billed hat too.
[00:00:37] Eric Knight: Uhh, flat billed is probably better because we have an internal bet going on. And I think more people will like flat.
[00:00:44] Jarred Morgan: Well, what's the topic today, buddy?
[00:00:46] Eric Knight: Today's topic is understanding calcium hardness. We have been covering the LSI. The first few episodes were about alkalinity and pH. And as you know, that's two of the six LSI factors. The last episode, we talked about water temperature. So today we are covering calcium hardness. And of course the next two episodes we'll finish out the six factors of the LSI. So as a recap, the LSI, the Langelier Saturation Index. It is the objective way that we measure water balance. And there are six factors. So we're going to cover it. We just have a few takeaways. Three of them today, uh, calcium hardness is the most stable of the six LSI factors. And therefore it should be the foundation for your strategy. Water temperature, we said last time, that's the moving baseline, but calcium harness really doesn't move unless you move it.
[00:01:37] The second takeaway is calcium, surprisingly, is not the leading driver of carbonate scale. Everyone thinks it is, "oh, I have too much calcium. Therefore I have scale."
[00:01:46] That's actually not true. It's just one of the contributing factors and it's not even one of the major ones. And we'll get into that. And the final takeaway is we're going to discuss what can raise calcium hardness levels, you know, beyond just adding it with calcium chloride. And the few things-- there's only two of them that we can think of that actually lower calcium hardness. So Jarred, you ready to get going?
[00:02:10] Jarred Morgan: Ready?
[00:02:10] Eric Knight: All right. Without further adieu, episode six of the Rule Your Pool podcast, understanding calcium hardness.
[00:02:23] Welcome to Rule Your Pool. The podcast by Orenda that explains and simplifies pool chemistry that anybody, regardless of experience, can understand it. I'm your host Eric Knight, bringing clarity to these subjects so that you can bring clarity to your water. If you're ready to rule your pool, then let's go.
[00:02:45] Okay. So of the six factors of the LSI, calcium hardness is one that people don't measure very often, but it's probably your best friend. And in the last episode, we talked about water temperature because water temperature is certainly the most ignored. I would say it's the most neglected because people just don't think about it.
[00:03:04] But you can't really control temperature unless you crank up your heat. And you just have to adapt because it moves. Calcium hardness really doesn't move unless you move it. You know, regardless of temperature, your calcium hardness is going to stay remarkably consistent throughout the course of the year.
[00:03:20] And that's a really good thing. So if we set it at say 300 ppm, There's a good chance it's going to be about 300 ppm next month, depending on the type of chlorine you use, and depending on how you treat that pool. For instance, do you add acid properly? We'll discuss that in the third takeaway of what can actually affect your calcium hardness levels.
[00:03:45] But the point I'm trying to drive at is it's remarkably consistent. Now, Jarred, you've got a pool. Where do you keep your calcium hardness level?
[00:03:53] Jarred Morgan: My calcium hardness level is roughly 500 or 550 parts.
[00:03:58] Eric Knight: Whoa. Time out, bud. Let's pump the brakes. 500 to 550. What does the textbook say? It should be?
[00:04:05] Jarred Morgan: 200 to 400.
[00:04:08] Eric Knight: Okay, so you are in deliberate violation of textbook range chemistry.
[00:04:14] Now you heard it here first. If you didn't already know that. We don't always abide by textbook range chemistry because we at Orenda, we preach a philosophy that is LSI first, range chemistry second. And this is especially true for calcium hardness. Depending on where you are. You may need a lot more than 400 ppm. I guess I shouldn't say a lot more. You may need more calcium hardness than 400 ppm, especially in colder climates.
[00:04:43] Jarred Morgan: I wouldn't say you need more. Um, I think it's something that people get scared of or paranoid of. So they try to keep it as low as they can in fear of scale. But it's not that you may need more, it's just, we can manage our water with more. A lot easier, in our opinion. You don't want to be scared of your calcium level.
[00:05:04] Eric Knight: Oh, absolutely. As Harold likes to say, calcium is treated like it's a four letter word. In reality, it's your best friend because it doesn't move. And it is also not the leading driver of scale, which is our second point here. But what I want to say is because it's so remarkably consistent, that is the foundation to build your chemistry strategy around. So if you have this rock solid foundation, an analogy is kind of like if you were willing to build a house, would you want to put it on a marshland, like a muddy swamp? Or do you want to build a solid foundation?
[00:05:40] Calcium hardness is that rock solid foundation, because you know, if all other factors change, you at least have that many parts per million of calcium hardness, which is going to help you stay within LSI balance regardless of your other factors.
[00:05:53] Jarred Morgan: Now I can hear some naysayers thinking in their head right now. "Well, what if I live in Southern California in the desert or in Phoenix? And I get roughly six feet of evaporation a year. That's going to artificially increase my calcium and TDS level."
[00:06:10] Eric Knight: Mhmm. Continue your thought. I like where you're going.
[00:06:13] Jarred Morgan: They're saying they can't get a pool at, say 400 or 500 parts calcium cause that's just going to skyrocket over the course of a normal swim season.
[00:06:22] Eric Knight: Right. You're absolutely correct. Um, I would actually add on to that, that there's a common thought in places like Phoenix. We've been there a lot, you and I. Where everyone says, "oh, we have really hard water here." And you would be right if you were getting well water out of the ground in Phoenix. But municipally treated water? I've been there. I've tested a lot of tap water. I haven't seen anything over a hundred yet. Now, granted, I'm sure it exists.
[00:06:46] Phoenix is a huge valley. But I haven't seen anything over 100 ppm, which means that the municipal treatment plants are softening the water. Because I bet faucets and all sorts of other things were getting scale problems.
[00:07:00] Jarred Morgan: You're absolutely right. In a funny, funny, just quick test that I like to tell companies, when I go do a training or something.
[00:07:08] I'll ask them if they have soft or hard water. And generally speaking, obviously a few know, but somebody's like, "oh yeah, it's hard." Well, there's a quick test you can do. If you go wash your hands and it feels like you can never get the soap off your hands, you have soft water.
[00:07:23] Eric Knight: Yeah. Or you could just take your test kit to your sink, where you wash your hands.
[00:07:27] Jarred Morgan: Who uses test kits? Dude. Nobody uses those things.
[00:07:30] Eric Knight: Well, Hey, you know what? We preach on startup, especially, but for every pool you get, you have to know what the tap water chemistry is.
[00:07:38] Jarred Morgan: But there is a preconceived notion of what your water makeup calcium level is, and in reality, it's way different than what you think it is.
[00:07:47] Eric Knight: Yeah. So if you listening, go on the Orenda blog or just go into the Orenda app, which, we mention this every episode, but it's just called Orenda, O R E N D A. It's free in the app store and Google play. If you go in there and you go to articles, and type in evaporation, There's an article in there called evaporation and accumulation. And it talks about exactly what Jarred just brought up.
[00:08:09] It talks about the fact that hotter climates lose a lot more water. And when water evaporates, it leaves everything behind. All of its salts, all of its minerals, total dissolved solids, which includes, of course, calcium hardness. And so what happens is you lose this water, then you replenish from the tap.
[00:08:26] And that will actually accumulate more calcium hardness. Cause you have some in your tap too, even if it's a low number, the fact that your minerals just accumulate over time, much like cyanuric acid does, you get more and more over time.
[00:08:40] Jarred Morgan: There are some places that have 5 - 10 parts calcium out of the tap.
[00:08:46] Eric Knight: Oh yeah.
[00:08:46] Jarred Morgan: Which is a completely opposite problem. But yeah.
[00:08:48] Eric Knight: Well that's true. But in high evaporation areas, you just have to kind of be aware that these numbers can accumulate over time. Um, so yeah, you shouldn't personally raise it in Phoenix to something like 500 if your tap water is, let's say 80, you should probably raise it to more like 250 to 300, because over the course of that season, it'll probably get to almost 500 by the end of the summer.
[00:09:12] Jarred Morgan: And that's exactly where the point is. The point is if you are in a hotter weather climate, you know, you need to run a more conservative level of calcium hardness.
[00:09:22] Eric Knight: Yeah. So let's talk about how we actually test that. There's electronic test kits that are pretty accurate, although there's questions in the industry of how accurate, which test is which. We're not getting into that. That's not our business.
[00:09:34] Just make sure whatever test kit you're using is calibrated and it's treated well and you don't leave it out in the sun all day.
[00:09:39] The most common one that we think of as a reagent test kit. A titration with drop kits, right? And you, you put all these drops in and I use one of those kits around here.
[00:09:50] I also use digital. I also use strips here and there. But basically I use whatever the customer has. Because when I fly around the country, I guess, pre COVID. I can't fly with my test kit. Liquids are not allowed on flights. So even if they're all in small little bottles, it's just a pain. So I always use whoever's test kit is there, so it's always something different.
[00:10:13] How many times, Jarred, have you tried testing calcium hardness, and then you get like those little pink flurries or flakes floating around in that sample.
[00:10:22] Jarred Morgan: It takes a lot longer to get it to turn purple or blue, I guess I should say...
[00:10:27] Eric Knight: supposed to turn blue, yeah,
[00:10:29] Jarred Morgan: but it turns purple and it seems like it sits on purple and no matter how many drops I had, it's just always floating balls into the cylinder.
[00:10:37] Eric Knight: Well, I was just on the phone with Wayne from Taylor. Taylor is the leading manufacturer of those type of test kits. And he was saying that those little pink dots are magnesium hydroxide, and part of the issue of why the color won't change, normally you can still get it to flip, but you'll have these little floating dots, but if you have enough copper or iron in that water too, the color of the sample won't actually change.
[00:11:01] And so what he advised is, he said, I think the number 12, the last, the titration one that you'd count the number of drops, put five of them up front because they have a sequester in it and that'll take the iron and copper out of the equation and then go through the test and just add that five to the total number.
[00:11:18] And that way kind of gets ahead of it and you'll be able to do it. There are other test kits and methods to testing, but what we need for the LSI is not total hardness. We need calcium hardness, and that's what that titration test does. It takes the magnesium out of the equation, because if you add magnesium and calcium together, you'll get total hardness. We just want calcium hardness. So that's what that's all about.
[00:11:45] Now, soft water versus hard water is, I mean, there's a lot of different ways you could soften water there's magnetic systems that can do it because at the end of the day, calcium is technically an alkali earth, metal, believe it or not. Did you know that, Jarred?
[00:12:01] Jarred Morgan: Not until we started selling our scale and metal control product. It's the reason why we call it a scale and metal control product, but we really, we should just call it a metal control product.
[00:12:09] Eric Knight: Yeah. Well, yeah, it's, it is kind of confusing. I didn't learn it until I was at, I think the NPC conference and said, oh yeah, calcium is an alkali earth metal. Really? And then you think about it. I mean, magnesium's a metal. But we also call these things minerals. So if we refer to them as minerals, that's why.
[00:12:27] Jarred Morgan: Minerals is a lot more appealing to the ears. Trust me.
[00:12:30] Eric Knight: Yeah. Cause when I think metals, I think iron and I think copper, I think silver, and those kinds of things, but calcium technically is a type of metal.
[00:12:38] And so. By getting the calcium down, your water takes on new properties. And we don't need to go all the way into them. That's much more of a drinking water conversation. And like you said, soft water has a lot harder time getting soap off of your hands. Hard water is very easy to get soap off your hands, but it will also leave things like white dry marks on your dishes in your dishwasher. You've probably seen that too. Now. Jarred, why do you think that happens in hard water dishwashers?
[00:13:11] Jarred Morgan: Probably because there's more calcium left behind after the dishes dry.
[00:13:16] Eric Knight: It is, there's some evaporation, but it's really because of heat. And that is bringing me into our second takeaway.
[00:13:25] Of course, the first takeaway we just covered was that calcium is your friend. It is the most stable of the LSI factors. It doesn't move much unless you move it. The second takeaway here is that calcium hardness itself is not the leading driver of scale formation. I'm going to repeat that calcium hardness is not the leading driver of scale formation.
[00:13:49] And it's easy to get confused about this because when you look at scale, Jarred, what does it look like?
[00:13:54] Jarred Morgan: It's white calcium.
[00:13:56] Eric Knight: Yeah. It's calcium. I mean, it, common sense would say, oh, I clearly have too much calcium hardness because I'm looking at calcium. Well you're actually looking at calcium carbonate. That calcium carbonate is determined by the LSI. Not just calcium harness and calcium harness is just one of six factors that precipitated that.
[00:14:16] And come to find out it's like the fourth most important one out of the six. The number one driver of scale is the pH. You get a pH over 8.2. I mean, you could still have scale at like 7.8 depending on other factors, but if you get it over 8.2, you have a very high probability of scaling.
[00:14:37] Number one factor is pH. The number two factor is water temperature. We touched on that in the last episode because pH will largely precipitate calcium, but temperature is what determines where that calcium precipitates. Remember we talked about salt cells and heat exchangers and sunny tile lines?
[00:14:59] That's a temperature thing. The next biggest factor, you could argue because they're very similar, it's either alkalinity or it's calcium hardness. But neither of them are even remotely close to pH or temperature in terms of precipitating calcium scale. And that's a big misnomer,
[00:15:14] Jarred Morgan: Which is a big point here because there's a lot of commercial pools that use Cal hypo tabs as their primary sanitizer that have calcium levels up near a thousand.
[00:15:26] Eric Knight: Yeah.
[00:15:26] Jarred Morgan: But they don't have scale.
[00:15:28] Eric Knight: Right. Because they manage the LSI or a similar index, like the Ryznar. A lot of our commercial customers use Cal hypo every day. And Cal hypo, I hope I have the number right, is about four parts per million of added calcium hardness for every pound of Cal hypo in 10,000 gallons.
[00:15:49] That's a mouthful, but basically it will slowly rise your calcium hardness. And of course over time it rises significantly, but not over the course of a week or two. You don't really notice it. But if you are using Cal hypo as your primary chlorine, you know it's going to go up.
[00:16:05] Jarred Morgan: Unless you're abusing the use of Cal hypo. Cause you have to shuck your pool too often or over shock your pool.
[00:16:11] Eric Knight: Right. If you're struggling to have breakpoint chlorination, because you have too many nitrogen compounds and you have to keep shock, shock, shocking. Well yeah, your calcium's going to rise pretty quickly. So just be aware of that, but we're going to touch on other things that raise calcium hardness in just a minute.
[00:16:29] The point here is: high calcium hardness itself is actually to your advantage. Use the Orenda app LSI calculator. And you'll see what I mean. You can have high levels of calcium and not have scale. The real question is where do you keep your alkalinity? And how do you contain your pH?
[00:16:50] You don't want to control pH cause it's going to rise naturally through physics. So where do you contain it? Our thought, and we'll have Jarred touch on what he does in his pool, our thought is have a little bit more calcium hardness and have a little bit lower alkalinity. The key here, if you're going to lower, the alkalinity is you have to measure your acid because alkalinity is what protects the downside.
[00:17:11] If you drop out your pH too much alkalinity protects. But if you're measuring your acid and adding it correctly, you don't need nearly as much as the textbook might say. Would you agree with that Jarred?
[00:17:22] Jarred Morgan: Absolutely. And I know, like I said, we've touched on, uh, my pool and where we keep it over the last couple of episodes. So if you've listened to those, this is obviously nothing new. But yeah, I maintain my my alkalinity around 60 parts per million. That way I have a higher calcium hardness. So they offset and I'd rather have a higher calcium hardness, because, like we're talking about here in this episode, it's way more stable and predictable and managable versus bouncing the pH and alkalinity back and forth with one another.
[00:17:51] Eric Knight: Right. Well, how about cost-effectiveness? If you're a pool service pro listening to this, you service multiple pools every week. Bicarb is not free. You could set your calcium hardness to a good position. And if you don't know what that is, contact us. You can contact us directly through the Orenda app or on social media.
[00:18:11] We get questions all the time. If you're going to take one sentence out of this, I guess this would be it for the whole episode. The ideal calcium hardness level for your pool is whatever allows you to maintain LSI balance year round.
[00:18:27] That's it. And it's going to be very different in Wisconsin than it is in Tucson, Arizona. Because the climate is different. The temperature parameters are different. Their winter in Wisconsin is going to be freezing that pool. Tucson doesn't have that. And so there's a big difference in what that pool is going to need LSI-wise in the summer and the winter.
[00:18:49] It also has to do with the amount of sunlight it has to do with how much evaporation you're gonna have. If you need help with it, just contact Orenda, we can help you out. So all that is to say, don't freak out about slightly higher levels of calcium hardness, because you can actually replace your LSI value that you would have had with 80 to 120 alkalinity with a higher level of calcium hardness, and you can have a lower alkalinity.
[00:19:16] Play with it on the calculator. You'll see it in real time. You can still have LSI balance. And the nice thing about having the higher calcium is it doesn't move. That's the key here.
[00:19:28] Jarred Morgan: Well, the other thing that adding bicarb to your pool constantly and playing that game is I noticed it the first year, roughly when we built our pool, I was adding a lot of bicarb, my salinity level got pretty high.
[00:19:42] Eric Knight: I bet.
[00:19:43] Jarred Morgan: So, you know, sodium part of that bicarb definitely has a factor here.
[00:19:48] Eric Knight: Oh, for sure. It absolutely does. So. I guess trying to wrap that up is don't be afraid of high levels of calcium because it's going to lead to problems. And I'm going to give you one real world example and a very, very costly example.
[00:20:04] And it affects pretty much everywhere that pools freeze. Jarred, you know exactly what I'm about to say,. But for the audience listening, several years ago, I went into the Northeast. It was in Pennsylvania and then the next day was in New Jersey. And the next day was in, um, like Albany, New York. And the first day I was told, "oh, go to this customer. They have a recurring scale problem."
[00:20:28] Scale. Okay. Scale, no problem. And I go to meet this customer and they start showing me pictures, telling me the symptoms. And I'm looking at it and thinking that doesn't, that doesn't look like scale. You have all your water chemistry records. I plug in the water chemistry records and nothing is adding up here.
[00:20:45] I'm thinking we drop the temperature. You're not getting a high LSI. You're getting a very low LSI. And what the customer said. And by the way, if you're listening to this, call me if I'm wrong on this, but I'm pretty sure it's a direct quote. "You've got to be effing kidding me."
[00:21:02] Because for so many years, what he had been doing was lowering the calcium hardness or keeping it to a low enough level going into the winter time so that they didn't have scale when they opened up in the spring. Because everybody thought it was scale.
[00:21:20] Well, one simple look at the Orenda calculator said that's not possible. That's not scale. And then I started asking questions, like, was it on light fixtures? Was it on the face of tile? Or was it between the tile? Only on the grout? Come to find out it was not on any plastic, light fittings or anything like that.
[00:21:39] It was only coming out of the plaster. In fact, it wasn't even on the pebbles, in the plaster. It was between it, in the cement. I said, these things are growing. Come to find out, they're crystals. They are a type of calcium carbonate, but they're just a much denser type. And they are called calcite crystals.
[00:21:56] They are not scale. They're formed by a low LSI violation. And it was a consequence of thinking that too much calcium hardness was a problem. It was not a problem. They didn't have nearly enough to get through the winter. So if you're going to feed your pool, going into the wintertime, feed it calcium. Feed it calcium. And that right there, being able to balance your LSI at the lowest degree that you're going to have, say it's 40 degrees or 32 degrees in their case.
[00:22:28] If you have enough calcium hardness, it will stay in solution in cold water, which brings you to a little bit of a tangent before we get to our last point here. Um, most things dissolve better in hot water, right? They'll stay in solution better. If you heat up, you can dissolve more sugar or whatever you have.
[00:22:45] Calcium is the opposite. The colder the water, the better calcium stays in solution, which is why cold water makes water more aggressive. Because it's hungrier. It wants more calcium. So the colder your water, you can load it up with calcium hardness. And, um, you know, the hotter, the water, of course you precipitate, like we discussed last episode.
[00:23:05] So Jarred, any comments here before we get to the last takeaway?
[00:23:08] Jarred Morgan: No, uh, I know I've run into a couple of situations where houses have water softening systems for their home. And a lot of times we'll fill a pool up or, you know, we'll maintain a pool and not realize, or really it's just ask the question. Is this spigot I'm feeling this pool with tied to your water softening system?
[00:23:28] Cause if it is, you need to take that into account when you're maintaining that pool, because you're not going to be adding calcium through the tap water, which means you're going to have to artificially add it during your maintenance.
[00:23:41] Eric Knight: Or your start-up.
[00:23:42] Jarred Morgan: That for sure. No question there, but just normal routine maintenance, your calcium level is going to drift down, especially if you're using a liquid chlorine as your sanitizer.
[00:23:52] So you're gonna have to artificially account for that when you're doing your weekly maintenance.
[00:23:56] Eric Knight: And Jarred, that brings us to our final takeaway here. There are many things that can raise calcium hardness and we'll cover them, but there's only two ways to lower calcium hardness.
[00:24:06] The first is obviously to drain and dilute. Same thing for reducing CYA, same thing for reducing salt or TDS. Drain some water, dilute it with fresh water.
[00:24:16] This, of course, for calcium depends on the calcium hardness of your tap. If you have a thousand calcium hardness out of your tap, draining the pool and replacing it with that is probably not really going to do you much good.
[00:24:27] Jarred Morgan: That's when you're gonna run it through an R.O. system of some sort.
[00:24:30] Eric Knight: Correct. Reverse osmosis will get rid of calcium hardness, and TDS and all sorts of other stuff. I guess there's three ways then, not two, cause I didn't think about R.O. Good point. So diluting is the main one.
[00:24:41] R.O. is the next one, especially if you're in like a drought stricken area that you're not allowed to drain, reverse osmosis is a good, um, a good alternative.
[00:24:50] Jarred Morgan: There are companies that have a trailer that you run the water through that will purify that water. There is some, there is a waste to that, and I think it's gotten better over the years, but last time I heard it was 15%?
[00:25:03] Eric Knight: Yeah. But I mean, even if you only R.O. half your water, you're going to cut down your calcium hardness in half and your total dissolved solids and your CYA and all that. So just keep that in mind that that is an alternative. There is another way that you can lower calcium hardness without lowering cyanuric acid or TDS. And that is by throwing soda ash into the pool.
[00:25:24] Jarred Morgan: Ahh I was going to say, I think I know where you're going with this.
[00:25:27] Eric Knight: It's a terrible idea. If you're listening and you, you don't want this science experiment, uh, just don't do this. But if you really...
[00:25:36] Jarred Morgan: Sure, it's been done. But boy...
[00:25:38] Eric Knight: If you really want to get rid of calcium, you can force an LSI violation really rapidly by throwing soda ash into the pool.
[00:25:47] And if you've ever put in soda ash too fast, it'll cloud up and you're like, "no, no, no, no, no, no, no." And it just takes over your pool. What you're watching is a real-time LSI violation. And it's converting bicarbonate alkalinity to carbonate alkalinity. It's binding with calcium, it's turning white and it's falling out as dust.
[00:26:06] And you can vacuum that dust out of your pool and lower your calcium hardness.
[00:26:09] Jarred Morgan: Specifically, you can vacuum that calcium carbonate straight out of the pool.
[00:26:15] Eric Knight: Oh yeah, you absolutely can. You can vacuum it out. Now. We don't recommend this method unless you're up for a four day excursion and seeing how fast your pool can clear and fall, and you'd have to shut off circulation because your filter will capture it. It's a mess. But technically that is a way to lower your calcium hardness.
[00:26:33] Jarred Morgan: Technically, yes, but let's steer away at that one. Uh, but yes you can.
[00:26:37] Eric Knight: Yeah. Hey, you know what? We're, we're here to be honest brokers of true information. We don't want to leave it out because let's be honest. It is the coolest of the ways. It's also just the biggest pain of all of them. So just drain it, dilute if you need to lower it.
[00:26:51] So, let's talk about what raises it and then let's wrap this episode up. Obviously calcium chloride. That's the product that we use. It comes in three different forms. Usually you'll find two very easily.
[00:27:01] You'll see either 77% flake, which is what almost everybody uses. And you can also see 94% prill or granular. There's also calcium chloride powder. That's a lot more expensive. It's harder to come by. Not every distribution place sells it. Not every retail store sells it, but calcium chloride, CaCl, or CaCl2 actually.
[00:27:24] When you add that to water, the chloride will separate out and you get calcium hardness in your pool. It gives off an exothermic reaction, which means it gets really piping hot. So you have to be careful when you mix this. This is why for the Orenda start-up we have a special barrel that is rated for 250 degrees Fahrenheit, much hotter than the boiling point.
[00:27:44] Didn't you have like an infrared thermometer and it got up to like 190 degrees when we put all that calcium in the barrel?
[00:27:50] Jarred Morgan: I don't remember what the temperature got up to, but it was a 30 gallon barrel and we put over a hundred pounds of calcium chloride in there.
[00:27:56] Eric Knight: It's stupid. Don't ever do that. We did it as an experiment.
[00:27:59] Jarred Morgan: It was a lot. Just to see how hot, yeah.
[00:28:02] Eric Knight: We were, we were getting our Bill Nye on. And we were just doing our best to see how much that barrel could actually take. And it, it handled it, but it got hot. Like you could have burned your hand touching the outside of the barrel.
[00:28:13] It was so hot. So be very careful when you mix it. Dilution is the solution. The more you can dilute it, the less risk you're going to have. And another way to get that calcium into solution is to chelate it. This is where SC-1000, our product SC-1000 comes in. If you put just a little bit, say you have a five gallon bucket and you're dissolving 15 pounds of calcium chloride, what, what would you say, a tablespoon of SC-1000 should be plenty for that amount.
[00:28:41] Jarred Morgan: Yeah, not a lot.
[00:28:42] Eric Knight: Not a lot teaspoon, tablespoon? That will help substantially to dissolve that. But here's what you have to be aware of: SC-1000 has a pretty high pH. So you have to have a little bit of acid to offset that. For every quart of SC-1000, it takes 12 ounces of muriatic acid just to neutralize its pH.
[00:29:01] So be aware of that. Uh, if you didn't have SC-1000, just putting a teaspoon of muriatic acid in that bucket will also accelerate it going into solution. So of course you can add it, number one, by adding calcium chloride. Number two, Cal hypo. We discussed this a little bit earlier. I believe it's about four parts per million per pound of Cal hypo per 10,000 gallons.
[00:29:24] So it's not a huge way to raise it, but if you shock enough or if you're just using Cal hypo year round, your calcium hardness will go up.
[00:29:32] Then there's the bad ways to get it up. And that's usually the abuse of acid, which causes etching of a plaster surface. And it steals calcium from your surface. From your cement, from your plaster, whatever you want to call it. When your calcium quote-unquote.
[00:29:49] And for those of you not watching, I'm using air quotes, "drifts up." That's a lot of cement. And for a typical 20,000 gallon pool, we've heard two different figures. I'm not sure where it lands. But, um, if your pool on a startup, let's say your tap water is 80 and it drifts up a hundred parts per million on its own to 180. On a typical 20,000 gallon pool.
[00:30:11] That's about 33 pounds of cement. I've also heard 16. So we're kind of like one is half of the other. I'm not sure exactly what it is, but either way, that's a lot of pounds of cement that, that water dissolved to try to get its calcium hardness up. So you can either feed the water the calcium it needs with calcium chloride, or it will feed on its own to balance the LSI.
[00:30:33] Jarred Morgan: I went and looked at two jobs for a pool builder here in north Texas. Both of these houses were next door to each other. So the exact same water, and one of them was, uh, they did a hot start on or zero out, start on it. And the tap water was, you know, 120, but on the first pool I went to, the pool water measured about 250 calcium hardness.
[00:30:58] No hot start on that pool. I went to the pool next door. They did a hot start on it and it was over 500.
[00:31:05] Eric Knight: Oh my gosh. Well, where do you think it came from? If you didn't put it in, where did it come from?
[00:31:10] Jarred Morgan: Oh the plaster was absolutely torched. It was rough as can be. The spa was a different color than the pool. A lot darker in the spa than it was in the pool. And you can see, you noticed areas in front of return lines where you could tell the acid was blowing the water on the surface and it was just eating it up.
[00:31:28] Eric Knight: Yeah, well, that's pretty much it. I mean, the summary of this entire takeaway is if you didn't put the calcium in, either through calcium chloride or Cal hypo, it came from somewhere.
[00:31:41] Now that brings us to the last place. And that would be the tap. You need to know what your tap water chemistry is for every parameter, but especially calcium hardness. pH can fluctuate in tap water pretty rapidly. Calcium hardness does not. They have to fundamentally change something in the municipal treatment plant, but calcium hardness is pretty stable, I should say?
[00:32:02] I mean, you have to actually really change how you treat the water. Whereas pH can fluctuate depending on how far the pipe goes.
[00:32:08] Jarred Morgan: Well it's because most cities get their water from a specific source that does not fluctuate very much, unless there's a drought or some unforeseen circumstance going on, they're having to manage.
[00:32:17] But for the most part, it's the same water they're treating it the same way.
[00:32:21] Eric Knight: Well, I'd go even further than that. I've been in a neighborhood in Florida where this one house we were at, because the pool service company did everything on that street, this one house had like 50 calcium out of the tap. The one across the street had 90.
[00:32:33] I mean, literally across the street, not even a hundred yards away and completely different calcium tap. Come to find out, they're coming from two different treatment plants. So you have to kind of look into that don't ever, ever assume that you know what the calcium hardness is.
[00:32:48] So, anyway, I want to wrap this up. Um, do you have any final comments here, Jarred, before I wrap up these three takeaways?
[00:32:54] Jarred Morgan: No. My final comment is, you know, we didn't really touch on how often calcium hardness should be tested. But I think, in our opinion, at least every three to four weeks is a good baseline since it doesn't fluctuate much, you know, that's a good thing to check every three to four weeks.
[00:33:06] Eric Knight: Yeah. I like it monthly, you know, especially if you set it to where it is and you're managing the LSI every week and you're measuring acid, you're not column pouring it. You're not overdoing it. Then your calcium is going to be remarkably consistent. It's going to go at the exact same evaporation rate.
[00:33:19] It's going to go at the exact same rate of your chlorine. So it's a very reliable source. So, in closing, the three takeaways:
[00:33:28] Number one: of the LSI factors, calcium hardness is the most stable. Therefore it should be the foundation of your strategy. Pick a calcium hardness at an optimal level for your pool. And that optimal level is whatever allows you to maintain LSI balance year round for that pool. Colder climates, you're going to need more, you're going to need 400 to 500 or so. Maybe in the wintertime go over 500. Trust me, it'll dilute with rain. You know, rain is a great way to lower the level over time because rain has no minerals in it.
[00:34:00] Evaporated water coming back in, rain and snow over the winter. You, you know, they lower the water level of foot. That will definitely lower the level. Like we said, dilution lowers the level. But you need that calcium in the off season, it is your best friend.
[00:34:18] Number two: the takeaway it is NOT the leading driver of carbonate scale. pH is.
[00:34:24] And what drives the location is going to be temperature. Then you have calcium and alkalinity, roughly the same magnitude of what is going to be a contributor to scale. So don't just expect that you have super high or too high calcium hardness, because you're seeing scale. You may not. You could scale up a pool at 100 calcium, which is, we would argue very, very low if your other parameters are out of whack.
[00:34:51] Finally of the things that can raise calcium hardness, we hope that what's happening is either you're putting it in, or it's accumulating over time through natural evaporation. Not from etching your surface and stealing calcium. And to lower it, of course, you either dilute it or you filter it out. So Jarred, any final comments?
[00:35:14] I feel like we covered calcium hardness pretty in-depth...
[00:35:17] Jarred Morgan: I was gonna say, we touched on this subject. About as interestingly as you possibly can.
[00:35:22] Eric Knight: Well, we'll have two more to finish out the LSI, then we'll get into a new subject matter. So thank you again for listening. This has been the rule your pool podcast. If you have any topics that you want us to discuss, just contact us on social media, Orenda technologies.
[00:35:36] We're easy to find. We're all over the internet. You can comment on the video below or in the comments below. I should say. I'm your host, Eric Knight. This has been my cohost, Jarred Morgan. Thank you again for all your time. This has been episode six of rule your pool, understanding calcium hardness. Take care, everyone.
[00:35:55] Thank you for listening to rule your pool. A podcast by Orenda technologies. For more information on what we discussed in this week's episode, check the links in the description or visit www.orendatech.com. I hope you find this show valuable enough that you tap that subscribe button and share it with your friends.
[00:36:17] You can also like us on Facebook and social media. With our help. You'll be able to rule your pool without over-treating it with chemicals and wasting money. I'll see you next episode.