After a brief overview explanation of calcium hardness, we discuss what raises and lowers it. In short, if your calcium is increasing, it's coming from somewhere. If it's decreasing, it's going somewhere.
00:00 - Introduction
00:47 - Happy Thanksgiving!
02:54 - What is calcium hardness?
03:50 - What raises calcium hardness?
06:49 - What lowers calcium hardness?
09:37 - Summary. Thanks for listening!
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93. 3/7 - What raises and lowers Calcium Hardness?
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[00:00:00] Eric Knight: Welcome back to the Rule Your Pool podcast. I'm your host Eric Knight with Orenda, this is episode 93. We are continuing with our seven part series on what raises and lowers specific chemistries. In the last two episodes, we talked about pH and alkalinity, and in this episode 93, the third of our seven-part series, we are talking about what raises and lowers calcium.
[00:00:24] We have covered calcium hardness in several other episodes. Episode 6, 21, 34, and we even did a four part series on calcium issues, 48, 49, 50, and 51 and episode 58. So there's plenty of information. You can go back on this podcast and here you can also find this information on our blog.
Happy Thanksgiving
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[00:00:47] Eric Knight: But before getting this, happy Thanksgiving everyone. This episode should publish the day before Thanksgiving, and I thought we should briefly mention some of the things we're most thankful for. First. We are thankful for the fact that we are in an industry that we love and that we get to help people solve problems on a daily basis.
[00:01:08] That is a wonderful thing to do. We are thankful that we live in an era where swimming pools are even possible because we could have just as easily been born in a different time where mere survival was questionable. We are so blessed to be alive in this day and age and to be able to do what we do. We are thankful that the people that preceded our generations laid the foundation for the lifestyles that we currently live in.
[00:01:31] And, you know, be it technological advancements or general knowledge of how the world works, we've got it pretty good. And we didn't have a lot to do with it. We are thankful to our creator who deserves all the credit for every bit of everything, and we would be wise not to forget that. All of everything that we have is on loan.
[00:01:51] And finally, we're thankful for you, our listeners, our customers, the people in our industry. Thank you for giving us the time, week after week. Thank you for your questions and feedback. Thank you for suggestions for episodes. Thanks for holding us accountable. Thank you for driving us to continue to make the time each week to create this podcast because without you, we might have otherwise given up on this already. It's a lot of work every week, and we do it because you're worth it to us and we kind of enjoy it now. But to be honest, when we started, it was a lot of work. And we did not feel like it was going to go on forever and ever. We thought, Hey, you know, we're just going to do a certain amount of these and then we're going to run out of things to talk about.
[00:02:35] That is not the case. The involvement from you has been magnificent, so thank you for that. We are incredibly grateful that you continue to find value in what we teach. And because of you, we're going to continue on this journey with you trying to do everything we can to help you rule your pool. So let's get into episode 93.
What is calcium hardness?
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[00:02:54] Eric Knight: Let's overview quickly what calcium hardness is. Calcium hardness is the amount of calcium carbonate in solution. And we measure this in parts per million, or for the metric community, milligrams per liter. Now, this is different from how saturated that calcium carbonate is, which is an equilibrium that we measure using the Langelier Saturation Index (LSI).
[00:03:38] I use the analogy of sugar in a drink to explain that, but, uh, we're not going down that rabbit hole in this episode. If you want to learn more about the LSI, go back to the first 10 episodes or so, and we talk about it in depth.
What raises calcium hardness?
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[00:03:50] Eric Knight: So let's just get right into it. What causes calcium hardness to increase? What, what makes it go up? How do you add calcium hardness? Well, if your calcium hardness is rising, calcium must be coming from somewhere.
[00:04:07] The easiest way to add calcium hardness is to dissolve calcium chloride and put it in your water. That's what we would do on a startup. That's what you would do going into the winter to boost your calcium hardness level so that you have enough calcium as the temperature drops to protect your pool and its surface during the winter.
[00:04:26] But you can also get calcium from your tap water. Much like in the last episode we said, your alkalinity of your tap water matters because if that's your replacement water, it either makes your alkalinity go up or it makes it go down depending on what it is.
[00:04:39] Well, it's the same with calcium hardness. If you have a lot of calcium in your tap, and let's say it's more than what you had in your pool. Well, it's going to go up faster. Now even if you don't have more, if you have been losing whole water and you replenish it, okay, the calcium might actually go down if you have low calcium, but if it's just evaporation, that calcium never went anywhere. So your calcium can just naturally accumulate if you have evaporation. And the tap water, regardless of what the calcium is, is contributing to it because it's just adding on to something you never lost.
[00:05:12] So that's calcium chloride and tap water. But there's also cal hypo chlorine. If you use cal hypo as a shock or if you have a cal hypo tab feeder, each pound of calcium hypochlorite chlorine in 10,000 gallons of water is going to leave behind about four parts per million of calcium hardness. Now it takes a while for that to accumulate, especially if you're only doing it like an occasional shock every few weeks.
[00:05:41] But a commercial pool on cal hypo as your primary chlorine, yes, your calcium hardness is going to rise because of that chlorine. The other way you get calcium is the water finds it. See, you either give the water the calcium it craves, or it's going to find it on its own. And that is going to come from cement.
[00:06:00] Usually a plaster finish. Plaster, quartz, pebble, any cementitious finish has a lot of calcium in it, and that water is going to dissolve that calcium if it needs to to feed itself. This is called etching. This would be a red LSI violation if you're looking at the Orenda Calculator. You do not want this. If you're going to raise your calcium hardness, you want to be the one to do it because if the water has to do it by itself, you messed up the LSI.
[00:06:29] Water only cares about equilibrium. It only cares how balanced it is, and that balance is measured using the LSI. So it's very important for you to keep it balanced based on what the water needs. And if it's not plaster, it's going to be tile grout.
What lowers Calcium Hardness?
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[00:06:49] Eric Knight: Now, what would cause calcium hardness to decrease? If you want to lower calcium hardness, you need to get it out of your water, and you can't just neutralize it like alkalinity. If you put acid in your pool, you're not getting rid of calcium. In fact, you may dissolve more from the surface and your calcium hardness goes up. The only way you get it out is by getting it out. Meaning dilution.
[00:07:13] That could be splash out or leak or extended backwash cycles, much like trying to get something like cyanuric acid out of your pool, which we'll discuss later in a future episode. You would have to get calcium out physically. Overflowing from rain and snow because there's zero calcium hardness in rain and snow. It's pure distilled water.
[00:07:33] When water evaporates, it doesn't take calcium with it. It's just pure water. So that kind of dilution will do it. You can, of course, drain deliberately to reduce it, but it depends on your tap water. What is replacing the water you're getting rid of? Again, if you have hard water, meaning, uh, high on calcium hardness, you might not be diluting calcium very effectively because it matters what you're replacing it with. So you have to replace it with softer water, meaning lower calcium hardness in order to get that number down.
You could force an LSI violation and vacuum out the calcium fallout
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[00:08:05] Eric Knight: Now there's another way you can do it, but it's a mess. It's a real pain, but it could be done. If you want to deliberately pull calcium carbonate out of solution, you can do that with soda ash. You force a high LSI violation, cloud up your pool like crazy, let it precipitate as dust to the floor, calcium carbonate dust, and vacuum out the dust to waste.
[00:08:31] I do not recommend this, but in some cases, particularly in places that you cannot drain very easily, like the desert and there's water restrictions, it may be a necessary thing. The most common reason you would do something like this is if you are out on well water in a rural desert area with very hard water out of the ground. Let's say you're on a well and you have 400 plus calcium out of the tap. Okay. It's hot. It's the desert. You can't drain your water because you have water restrictions. How do you get calcium down if your tap water is so high? Well, you can deliberately force it out of solution with soda ash. It'll cloud up the pool, precipitate dust, you vacuum that dust to waste and it saves you a lot of water and it gets your calcium down.
[00:09:21] But again, it's annoying. And you may have some actual scaling that occurs, so you might have to physically clean up for days after you brush that stuff out. So just be aware of it. I'm not recommending it, but it may be a necessary thing to do if you want to reduce it.
Summary
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[00:09:37] Eric Knight: And I think that's actually it for this episode. So to recap, if you want to raise your calcium hardness, you need to add calcium to your solution. Either you add it with calcium chloride, cal hypo chlorine, or tap water. Or the water finds it on its own because it's under saturated on the LSI and starts dissolving cement to get calcium out of it. You do not want that to happen. That would be permanent damage. It's much better for you to add it yourself so that the water is always in equilibrium on the LSI.
[00:10:11] Now, to get rid of calcium, you have to physically get it out. You either need to get it out by getting whole water out via dilution, or you can precipitate it out by force, although we don't recommend that unless it's absolutely necessary.
[00:10:27] Anyway, It's pretty simple. This is it for episode 93. In the next episode, we're going to talk about what raises and lowers cyanuric acid. That'll be episode 94. Thank you so much for listening to this, and happy Thanksgiving everyone.