Understanding Calcium, the bedrock of water balance | Rule Your Pool (Episode 115)
Episode 115 of The Rule Your Pool podcast. I'm your host, Eric Knight, with Orenda and I'm going to be honest with you, not a lot of show prep for this one, but it's okay because we had a friend to talk about this every single day. And the reason I'm doing this episode is because the questions continue to come in and the problems as a result of not understanding this continue to happen. In this episode, I think it's worth a deep dive into understanding calcium is the bedrock of water balance, in my opinion, and I'm going to make that case for you in this episode today, we as an industry tend to under dose calcium, and I want to get into that in this episode because a lot of the problems that we're getting this year on that help line and on ask at or read tackle them or just submitting a question to ask.orendatech.com, which is our help center and even podcast addiction to tackle. We're seeing all of your feedback and we love it.
Thank you so much for the feedback. And there's a common thread, not enough calcium. Let's get into it. Welcome to Raw Jordan, the podcast by Brendon that explains and simplifies pool chemistry so 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 roll your pool, then let's go. Now, I realize this is not the first episode where we've spoken about calcium. We actually discuss calcium in many of our previous episodes because we talk about the LSI So much. If you go back, you can listen to episodes six. I'm by the way, I'm scrolling through this as I'm doing it, so bear with me.
Episode 6, 21, 34, 41 And then the five part series was 48 through 52, and that was on the common calcium issues that you have. Episode 55 I know we talk about there because standardizing pool chemistry, namely using calcium as the foundation for that 59 on how to implement the around a program also using calcium as the foundation for that episode 93 raising and lowering calcium hardness and episode one and four on calcium sulfate crystal. And now this. We need to understand this because continually when people send me problem boules, they'll send me a screenshot of the render calculator, which is great, allows me to see the LSI and everything, sealing all of it.
And I see calcium less than 300. Now if you're in Miami, Florida, I understand that, but I'm not just seeing it in Miami, Florida. I'm seeing like 210 calcium in Massachusetts and I'm seeing 250 calcium in Oregon.
I mean, colder climates, that's not nearly enough calcium if you want to maintain Ellis balance year round, which of course, is our first pillar of proactive pool care, I'll say it again, in our opinion, calcium is the bedrock of water balance. So let's dive into that. There are two disciplines in water chemistry, water quality and water balance. Water quality is sanitization disinfection, water, clarity, making it look nice, oxidation or PE, etc.
And a lot of what we do at Orinda is on that side of the business. Our enzymes help with supplementing chlorine against the oxygen demand. Specifically, non-living organics and phosphate remover takes phosphates out of the equation and all those things are water quality topics. Water balance is about physical equilibrium, and we measure this using the Langlier or Saturation Index or LSI. Now there are some other indexes.
And by the way, I just recently learned that the plural for index is indices. You're welcome. If you got nothing else out of this podcast, you'll learn that the plural for index is indices. So take that for what it is and impress all of your friends at your next dinner party.
I know dinner parties are a big thing in the pool industry Of the 149 of you listening to this, I want you to all take that gem with you. So we use the LSI. Now, there are other indices like the Reisner Stability Index or RCI, and if you see it online, a lot of homeowners here probably reading forums online that may refer to just the site where the CSI, the CSI is the Calcite Saturation index or just the saturation index. Generally, those are referring to the LSI or almost identical.
If you're balanced on the LSI, you're probably balanced on the other ones too. But let's just stick with the LSI because that is the international standard and that is what we use in our calculator. The LSI is the measure of the saturation equilibrium of calcium carbonate. So what does that mean? I've used the analogy before and I'll use it again in case some of you listening have not heard the other episodes. So if I were to put sugar into a drink and stirred around, it'll dissolve and I add more sugar, it dissolves and eventually I add too much sugar and I can't get all of it to dissolve. And some of it just stays at the bottom of the glass.
You've probably seen this before. Now just stirring it or even shaking it is not going to do anything because the water is now oversaturated with sugar. So we're going to replace the word sugar with calcium carbonate. That's basically the LSI. If you have too much sugar in your drink, if you have too much calcium carbonate in those conditions, then you have a high LSI and you will have scale or you will have cloudy water or other symptoms where calcium carbonate is precipitating out of solution.
Basically the water is saying I can't hold all of this calcium, I have to get rid of some because water trying to get back into equilibrium. So it has to shed calcium to get back down into LSI balance. Now, on the opposite end, the low end of the LSI and if you're using the Aranda calculator, it would be a red number on the low end.
The water is actually hungry for calcium and so it looks for it and it dissolves it and brings it into solution when it finds it. But if you don't have a cement based pool and you have, say, a vinyl liner or fiberglass surface water, still going to look for calcium and it may destroy your surface looking for it, hoping that calcium might be on the other side of that vinyl liner. And fun fact about vinyl letters, there is actually trace amounts of calcium carbonate in vinyl. It's a bonding agent. I think.
Look it up pretty crazy. So it is in there and it actually increases the porosity and the vulnerability, I will say, of a vinyl liner. This is why liners fade. If they turn yellow, that's more chlorine in sunlight. But if they lose pigment like pure white and they just lose pigment, that's usually unless I violation and more porosity leads to wrinkling when there's temperature swings and other things. Maybe that's an episode or a series of episodes in the future.
But for right now, let's stick to the LSI Water only cares about equilibrium. We've said this in previous episodes because it's true and it's still true today. Water cares about equilibrium, doesn't care about you, doesn't care about us.
It doesn't care if it's green, it just craves equilibrium, it's physics. And that is an equilibrium of calcium carbonate. Now, I said earlier about the glass that in those conditions you are oversaturated. What I meant by that is what could we do to this water? What can we do to this drink to get more sugar, to dissolve? And what I teach this in classes, a lot of people will say dilute it. And sure, I could drink sugar water and fill it with tap water with no sugar and get that sugar to dissolve. If we're being literal in a pool, you could drain it and dilute it and replenish.
That could happen. And there's some math there because you've got to know what's coming back into the pool. But that's changing water. I'm asking, what can you do to this water to get that sugar to dissolve? And the answer is you can heat it up for sugar if you've ever seen sweet tea made.
I live in the south. They're almost boiling water when they add all that sugar to it because you can't do it at room temperature. Same water, same amount of sugar being added. And yet the saturation point is so much different.
And so if we take that concept to swimming pools now we're talking about calcium carbonate, which actually dissolves better in cold water, not warm water. Almost everything else dissolves better in warm water. Almost everything else dissolves better in warm water, but not calcium. Calcium is more soluble in cold water. And that's a really important distinction to make, because as the temperature of the water decreases going into the winter, the LSI is also decreasing.
It's becoming more aggressive. The water is hungrier for calcium. That's why we advocate for having more calcium, especially in colder climates. You need that insulation because that's what the water's craving.
As that temperature changes, the water wants more calcium. So either you give it the equilibrium that it craves or the water is going to have to find it. And we talk about these conditions and a week ago ad nauseum about the place. I would recommend listening to the first 12 episodes or so of this podcast where we go through each factor and talk about it in general. But there's six factors, and if you use board seven, you can change a lot of those factors.
And if you factorial six, that's 720 different combinations of numbers. Multiply that by the amount of numbers on each of the dials on the Orinda calculator and you literally have millions of ways to balance water. Water has to if it's out of balance. Water has two ways to balance itself. And while you may ignore the Yellow Sea, water can't. It's not like water.
Just I'd like to be balanced. No water has to be balanced. It's physics. So it either eats or it scales.
If it doesn't have enough, it eats. And if it has too much, it gets rid of it and it scales. Whether that's cloudy water or scale in the tile line or calcium flakes in a saltwater pool or in the heat or whatever it is.
That's why calcium so important. You want to keep that equilibrium. And in order to do that, you need enough of it. And a lot of people will look at scale and they'll think, you know, I don't want that much calcium because I'm used to having scale and I just have too much calcium in the water. And that's usually not the case.
No, it can be sometimes, but in our experience, it is rarely the driving factor behind scale. When we see scale, it is almost always a combination of too much alkalinity, which then drives the page up so that you have both a high and a high alkalinity. That is almost always the reason that you have scale in a pool that is almost always the reason you have flakes in a saltwater pool, too much alkalinity driving the page too high. Because if you play around on the yellow side calculator, the page has a massive impact on the LSI and it moves. This is why we've devoted so much of our teachings in the last several years to containing page and understood ending Henry's law of differential pressures. We need to understand Henry's law because it's happening whether you like it or not, he says.
Guarantee this gravity. We need to understand that if we don't contain the page, the page is going up anyway. I love asking this question in classes. If you have 80 to 1 toe alkalinity and you don't have an auto cover, you don't have a dry clear feeder and you don't have an acid feeder, nothing fancy about it. It's just a pool. Have you ever been able to keep the page below 7.8 after seven days?
And the answer is always no, because you can't. The alkaline is too high. It drives the tried on the Orinda app plug in 82 120 alkalinity. Look at the page ceiling.
Just click at the top left show secondary readings. Is that number above 7.8? Sure is.
Now if you have really high citric acid because you're using dry cleaner or whatever. Sure you come back after seven days is not going to be as high because you're lowering the carbon alkalinity, you're lowering the page ceiling. Well, we're advising you to do is have a little bit less alkalinity to minimize how high the ceiling goes. In order to have that lower alkalinity, we have to have more calcium to offset that.
On the LSI, it's okay to have more calcium, everything in moderation, right? I'm not telling people in Tucson you need 600 calcium. No, no, you don't need that in Tucson. But boy, could the people in Traverse City, Michigan use it, especially going into the winter through field experience alone. And please understand, people don't call us about their good pools very often. They're calling us for help with a problem.
So our experience is really dense with problem pools. And most of those problems, especially with anything calcium related, you know, etching discoloration of plaster or anything like that, it's almost always from a lack of calcium. Now, that may not be the only problem, but it is certainly one of them.
And why is that? And I don't know where it came from. This is just Eric speaking here. Where do we get the idea that 250 is optimal? I've never seen that in a book.
I know the book say 200 or 400, but who p250 again, seems kind of arbitrary. At least pick 300. It's right in the middle that I would understand, but 250. No, I don't want you to be one of those people calling about the same old problems. Take a critical look at the calcium on all of your pools.
If we go back to scrolling again, episodes 55 and 59 of implementing the around a program and standardizing pool chemistry, you're going to pick a calcium that works for you across all of the pools you service. And if you're a homeowner listening to this, ask yourself the questions How cold does your water get? If your pool freezes, you're going to need more if it never freezes because you're in south Florida, okay, You don't need nearly as much. The temperature doesn't justify it.
The big question I always get is what is the ideal calcium hardness for my pool? That's what people call and they ask or they email. And the answer to that is the ideal calcium hardness to rule your pool is whatever allows your water to stay else. I balanced year round. This includes containing week to week so that you don't have an LLC violation.
This also includes winterization off season whether you to rise or just have a cold season. And you may have to, by the way, you may be in the Northeast and you may bump it up intentionally to 500 something because it's going into the winter and then dilution from rain and snow happens during the winter and you come back and you might have to adjust a little in the spring up to maybe high three hundreds or 400. So there might be two. But in general, the ideal calcium is whatever allows your water to remain LSI balanced 365 days a year. It is the foundation. You don't want too much alkalinity because it's going to raise your age too much.
But calcium doesn't really move when it's in there. It's their water loves it. I'm not saying get crazy with it. Too much of a good thing becomes a bad thing. Like anything.
It just depends on where you are. So I'm just going to throw some quick numbers at you just to give you a concept that we do have this on our website as well. Let's say you're in a really hot climate that doesn't get cold during the winter, so I'm just going to use South Florida, Houston, Texas, that kind of thing.
Well, although Houston, Texas did have a freeze, so that was kind of an anomaly. But we'll use South Florida, that kind of climate. You probably want to have mid to high two hundreds on calcium hardness, maybe 300 that probably appropriate in the summertime in a very hot climate that does have a winter, though, like Phenix, Arizona, or Tucson or Palm Springs, those kind of areas. Houston, again, you probably want low three hundreds on calcium. Just check on it because I know in Phenix it can get cold water can get down into the fifties or even the forties.
So be careful on that. Let's say we go up to Northern California, mid to high three hundreds, maybe low four hundreds year round. Of course, you're going to have more going into the cold, right? So most people are going to be adding calcium in the fall and then checking it and making slight adjustments in the spring based on dilution in the Midwest, you need a lot more because your pools are all going to freeze. So I would say in the summertime, I mean, you're in the four hundreds already and then in the wintertime get over 500 before you winterize. Same with the northeast.
I live in Charlotte, North Carolina. I've aimed for 400 and it's hot. I mean, it is 90 some degrees. It's summertime and I don't have any scale. Now, granted, my number is a little bit lower now because we had a good week or so of rain.
And I'm going to test that now that I'm reminding myself, protested tomorrow and I'm going to need to re-up that. But the point is, I want low four hundreds in Charlotte, North Carolina. In Georgia, you probably want to be high three hundreds low for hundreds. And then going into the fall again, raise it up. Don't be afraid of these higher numbers, because how this is going to be managed is by having a little bit less alkalinity. And that depends on your chlorine type and the type of pool you have.
You know, the thought process goes and it's actually kind of funny. As an aside, you got a really cool email from a homeowner and he's an engineer and I knew based on the email he was an engineer before he even said it. But in his response to my response, he said, Well, as an engineer, I really like detailed responses and I know you're listening to this, so thank you for that. Glad we talked about it.
I called him back. As I said, Matt, you really got me thinking. He basically asked, I need to understand your thought process for how you pick an ideal calcium in alkalinity so that you can contain page. He didn't ask what should my calcium and alkalinity be in Phenix, Arizona, where he lives because I would have said probably low three hundreds on calcium in about 60 alkalinity but that's because I do it every day. It was a great thought exercise because I had to write out each step of what I do with the calculator to figure that out.
Well, now I just know it intrinsically because I do it all the time and I, I just have that gut instinct, know. So he's got a saltwater pool in Phoenix, Arizona, no cover. And a little bit of turbulence from a spa overflowing into the pool. And I said, okay, you should have about 300 to 320 calcium in the summertime and about 60 alkalinity. And I went through and I started jotting down my thought process like everything turn dial here, look at ceiling, adjust alkalinity, check, see white everything in order And it is just stop counting it 42 steps.
And I realized this is a really convoluted way of thinking, although it's so clear in my head. And if you do it all the time, it makes sense. Go in my ear and out the other and you'll get it.
So how do I convey that to you? And I'm going to try my best right here. Just think about two things above all. The first thing is what is the coldest water temperature your pool is going to experience when those are you in the Midwest, In the Northeast, you already know it's freezing temperature. It's 32 degrees Fahrenheit or zero degrees Celsius. Base your first decision on that.
And then the flip side of that question, what is the hottest temperature? Because the real question is what is the temperature delta that your pool is going to experience? What is the swing? Right? Is it going to be 88 degrees in the summer and 40 in the winter? What's the worst case scenario? And either direction, that's your starting point. That right there is going to give you most of your calcium answer. As for alkalinity, that's really more of a question on your chlorine type. If you're using trichlor as a primary, which we do not recommend as a primary, it's a nice secondary, but it's really not meant to be a primary.
You need more alkalinity. You probably need 80 to 90 alkalinity because you have an acidic chlorine that is constantly burning through alkalinity and the smoke is carbon dioxide. So you need more alkalinity in there to buffer against that chlorine. What about a salt pool or cal hyper pool or a liquid chlorine pool? What do you do about those pools? Well, in those pools you have lower alkalinity like 60. And if you're going to have that 60, you need to have enough calcium hardness to buffer against that.
So if you're going to reduce your alkalinity, you've got to raise your calcium hard. So the way I think about it is what is the temperature extreme and what is your primary sanitizer From there, maybe put one temperature on the left side of the calculator and the other extreme temperature on the right and start playing, figure out what you can do and just understand if the temperature swing is more than 40 or 50 degrees, you're probably going to need two different calcium numbers. You're going to need to boost it up in the fall, because if it's a temperature swing of 50 degrees, your pool's probably freezing. That's a really big swing. But for a lot of people, that's real and that's okay.
You're not alone. If you don't want problems to come back like calcite crystals, you should definitely be putting enough calcium in your water. I had these grand plans for this episode when I sat down. And of course, now that I'm here, not really remembering all of this, but I think it would be good to just touch quickly on what calcium hardness actually is. We measure calcium in our water as calcium hardness. Calcium hardness is expressed as parts per million of calcium carbonate, but technically, calcium carbonate is not really soluble.
So what are we actually measuring? We're actually measuring calcium ions, and those ions are called cations because there's two protons on it. What happens is elemental calcium K has two electrons on its outer ring that get lost pretty easily. I'm paraphrasing for the chemists listening to this. Sorry, I'm just trying to distill this and simplify simplified it loses two electrons so that it becomes net positive. So it's c a plus plus.
That means it's a cation, but we're just going to call it calcium ion. It's looking for and ions, it's looking for things with two negatives. The main one of course is carbonate co3 minus minus. So C a plus plus really likes co3 minus minus. But there are other than ions in fact calcium can bind to bicarbonate which only has one electron and it combined to sulfate, it can combine with phosphate if the conditions are right. So you get these other compounds, it's not just calcium carbonate.
You can have calcium silica calcium sulfate, which we talked about in episode one or for calcium phosphate, which is rare unless you have really high phosphate, really high temperature and a lot of calcium. As an aside, I have never seen calcium phosphate in a residential pool in going on seven years of being with around, I still haven't seen that calcium flakes in a salt pool are not calcium phosphate, they're calcium carbonate. Calcium phosphate is like khaki colored and I have seen it before several times, but it's always on commercial pools, on cal hypo feeders that are heated over 90 degrees and it's usually in the filter or the heater and it's like harder than concrete. You literally have to jackhammer a sand bed of a commercial filter and cut it out of the room because you just can't dissolve it. That's calcium phosphate and hopefully you never have that.
But the point is calcium iron in any of those forms is going to pick up on a calcium artist test, but it's expressed as calcium carbonate. And my understanding of this is because the molar weight of calcium carbonate is really easy to compare to water. So it's a great way to measure parts per million. Oddly enough, total alkalinity is also measured as parts per million of calcium carbonate kind of crazy, but again, it's a molar ratio thing, so don't get too confused on that. The point is when you're measuring calcium hardness, it's calcium ions in any of those forms. As long as they're in solution.
If you have precipitated calcium carbonate like scale on the tile line or flakes, those are not in solution anymore and therefore they will not be picked up by the test. So yeah, that's your your 101 on calcium. So I hope that helps. But here's the whole point of doing this. If you want to have less problems and less risk of discoloration on a plaster surface or fading of a vinyl liner or the chalking of a fiberglass pool, which will do an entire episode on that, to have enough calcium in your pool, water is going to be hungry for it. You might as well feed it, adjust your alkalinity accordingly after that, because the more calcium you have up to a certain point, the more options you have.
If I only have 250 calcium in a pool, I can't really afford to lower my alkalinity enough to contain at a reasonable ceiling without violating the LSI It's really hard to do, but if I have abundant calcium, I can afford to lower my alkalinity down to 60 and my carbon and alkalinity could be lower than that because I have CEA in my water. Or if you're using borate, all of those things, lower the carbon alkalinity. You can do that when you have a good enough foundation of calcium.
I've said it twice already in this episode, I'll say it one more time. Calcium is the bedrock of water balance and I hope you remember that. I hope this episode has been helpful for you. I don't know what your action step is going to be after this, but hopefully it sounds something like this. I need to have my guys test all of our calcium harnesses and write them down, and maybe you can start standardizing your pool just by getting calcium hardness in line based on where you are. That's a huge start.
That's a really, really good idea. Start ruling your pool, your calcium to where it needs to be. And if you have questions on how to do that, check out our Help Center, ask.orendatech.com. Check out our blog , blog.orendatech.com, or just our Web site. Find it on the navigation bar and search the word calcium. We have a bunch of articles and procedures about it.
You can also email firstname.lastname@example.org. But check the Help Center first. Check the blog first. It's a quick search bar.
See if we've talked about it. And if not, please do let us know because we are always looking for great information. And to those of you who do email us and give us feedback and ideas for the show and pointing out issues with the app or typos on the website. Thank you. I mean that. Thank you. It means a lot to me personally for the amount of effort that I put into this show that you are still listening, that you're getting value out of it.
And I hope this episode is no different. We make this show for you. If you have a chance to give us a review, give us an honest review.
I don't care what the star rating is in the podcast store or Spotify or wherever you are, as long as it's honest. We really appreciate it. I'm your host, Eric Knight with Orenda Take care, everyone. 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 the show valuable enough that you tap that subscribe button and share it with your friends.
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