Water Parameters That Actually Matter

Your pool isn’t misbehaving—your targets are. We take you past vague “ideal ranges” and into precise numbers that keep water clear, equipment protected, and algae out for good. Starting with the seven essentials—pH, total alkalinity, calcium hardness, temperature, TDS, cyanuric acid, and measured chlorine—we explain how each parameter supports the others and how to prevent scale or corrosion using the Langelier Saturation Index. You’ll hear why a steady pH of 7.5 and TA near 90 ppm form a stable base, how calcium should match your surface, and when TDS matters in both standard and saltwater pools.

The real unlock is the chlorine–CYA relationship. If you’ve ever watched algae bloom at 10 ppm chlorine, the missing link is cyanuric acid. We lay out Bob Lowry’s simplified approach: keep free chlorine at 7.5 percent of CYA for reliable sanitation, or 5 percent when borates are present. At 100 ppm CYA, that means aiming near 8 ppm FC; at 50 ppm CYA, about 4 ppm keeps water safer and clearer with less waste. Lowering CYA to around 50 makes daily control simpler, protects your budget, and avoids the trap of chasing “high” chlorine that still underperforms.

We also dig into borates as a practical upgrade. At roughly 50 ppm, borates act as an algistat, slow pH drift, and enhance clarity so chlorine lasts longer and works smarter. Pair borates with disciplined targets and an LSI calculator like the Arenda app, and you’ll stop reacting to blooms and start maintaining true balance. Whether you manage a service route or care for your own backyard pool, this walkthrough gives you a playbook: set firm targets, validate with LSI, align chlorine to CYA, and let borates shoulder the heavy lift against algae.

• pH at 7.5 for comfort and control
• Total alkalinity around 90 ppm to buffer pH
• Calcium hardness tailored to surface type
• Temperature and LSI to prevent scale or corrosion
• CYA at about 50 ppm for effective chlorine
• FC as 7.5 percent of CYA, or 5 percent with borates
• Borates at 50 ppm as algistat and pH buffer
• TDS as context, h

Support the Pool Guy Podcast Show Sponsors! 

HASA 
https://bit.ly/HASA

The Bottom Feeder. Save $100 with Code: DVB100
https://store.thebottomfeeder.com/

Try Skimmer FREE for 30 days:
https://getskimmer.com/poolguy 

Get UPA Liability Insurance $64 a month! https://forms.gle/F9YoTWNQ8WnvT4QBA

Pool Guy Coaching: https://bit.ly/40wFE6y

Chapters

• 1:51 Why Water Balance Matters
• 2:33 The Seven Core Parameters
• 3:50 Industry Ranges And Standards
• 6:05 Target Ranges Versus Ideals
• 7:35 LSI, Temperature, And The Arenda App
• 9:02 Practical Targets For TA And TDS
• 11:11 Calcium And CYA Targets By Pool Type
• 13:15 The Chlorine–CYA Relationship Explained
• 15:42 Applying The 7.5 Percent Rule
• 17:29 Lower CYA For Easier Control
• 18:59 Borates As A Game-Changer

Transcript

SPEAKER_00: 1:03

Hey, welcome to the Pool Green Podcast Show. I'm going to go back to the basics and talk to you about water balancing and the seven parameters or conditions involved in balancing pool water. I think you're going to get a lot out of this. Even if you are a seasoned pro, getting a refresher on what we're actually trying to balance is really a crucial thing to do in your pool care. Are you a pool service pro looking to take your business to the next level? Join the pool guy coaching program. Get expert advice, business tips, exclusive content, and get direct support. From me, I'm a 35-year veteran in the industry. Whether you're starting out or scaling up, I've got the tools to help you succeed. Learn more at swimmingpoollearning.com. When we talk about water balancing, you'll hear the word parameters thrown out there a lot. And that word is something that is used in the pool industry along with the pool water condition. And it's one of those things where the reason why they use these terms is because there are a lot of things to test for in a pool. There are a lot of parameters, and the main thing, of course, are these parameters I'm going to list here. And these are what we test for on a regular basis in pool water, and that is pH, total alkalinity, calcium hardness, your temperature, your TDS, your cyaneric acid, and of course the chlorine level, the free combined and total chlorine level of the pool. And these are your basic water parameters that you're going to test for in the pool. And there are some ideal ranges that have been industry standards for a very long time. These are established by organizations that kind of monitor and help the pool industry. And these standards are acceptable basically over the since I've been in the pool industry, these have been the acceptable standards of these parameters. For example, your pH, the minimum should be 7.2, and then the ideal is 7.4 to 7.6, with the maximum being 7.8. If you do commercial pools, these are really strict guidelines that the pool health department in your area, your local health department in your area, I should say, are looking for. Total alkalinity, the minimum would be 60 parts per million, and the ideal range is 80 to 120 parts per million. There's different, there's actually two different ranges that you get from different organizations. So I combined them. So 80 to 120, and then the maximum accolinity would be 180 parts per million. Your TDS, of course, is your total dissolved solids. There's a lot that goes into that. Basically, you would want to have that at 1500 parts per million above the tap water. And then you have calcium hardness, and it's area dependent, in my opinion, but the ideal is 200 to 400. So you kind of get the idea of these ranges. Cyaneric acid, 30 to 50 parts per million, with 100 being acceptable. In fact, most health departments will allow you to 100 parts per million, and then you have to do a partial drain of the pool. So these are some of the parameters in the pool. And I like Bob Lowry's target ranges, and that's what I use. Now, the reason why he has target ranges is because ideal ranges, there's a lot of variation for it, and it does cut create confusion out there, believe it or not, because you know you maybe you might have your alkalinity at 80. So what would be the ideal range? Well, there's there's really 80 to 120, there's there's a 40 part per million difference there. So to make things simple, Bob Lowry had created these target ranges, and I think they're very applicable to residential pool care as well as in a lot of cases to commercial pool care as well. And so his pH target range is 7.5. That's actually right in between the 7.4 and 7.6, and it makes logical sense that he would peg the pH at 7.5 in the pool. Now, if you're using the LSI, you know that you have to adjust for that. If you wanted to keep your pH at 7.5, you have to make some adjustments with the alkalinity and with the calcium hardness. And also temperature is one of the ranges parameters that you should be aware of because the water temperature does affect the LSI in the pool, the saturation index. Temperature is a key factor when you're doing these factors and you're trying to get the pool balanced and you're trying to make it so it's not scale forming or corrosive. So I definitely would, of course, recommend you to go to the Arenda app. Their LSI calculator is great. And this is also a factor that needs to be discussed when you're talking about water balancing. The total alkalinity, Bob Lowry has it at 90 parts per million, and that's the target range. Now, of course, if the pH is drifting up all the time, you would want to keep it at 80 parts per million, and this is something that you could do easily by adjusting the alkalinity down lower to keep the pH from rising rapidly. Now, TDS is really not super important according to Bob Lowry in his ranges here, but you want to have the maximum at 1500 over the startup. Now, if you have a salt water pool, you're gonna be way over that because salt is an element of TDS, and if you're at 3,000 parts per million of salinity in the water, your TDS is probably gonna be over 4,000 when you test it. So that's why he's saying that it's not a super important factor or a super important parameter in balancing the pool water. Now your calcium hardness, now this is something that I think really varies by region, and it's also a big factor in the LSI calculator. But the target range in a plaster pool for Bob Lowry is 350 parts per million, in a vinyl fiberglass pool, 250 parts per million. And of course, there's a lot to go with the calcium hardness, and I could probably do a whole podcast on that, but I'll leave it at his target ranges here for now. For cyaneric acid, his target range is 50 parts per million, and of course, the cyaneric acid level could go depending on a saltwater pool or your tolerance for cyaneric acid, I would say can go as high as 70 parts per million. I like to keep my saltwater pools at 80 parts per million, so I'm not opposed to 80 parts per million, even though 100 parts per million, I'm not really opposed to it if you understand the formula for balancing the free chlorine with a cyaneric acid level. Although I did mention chlorine as a parameter, it's not really a parameter and water balancing per se, but I have it here because it's an element that of course you need to test for, and the water balance is basically the equations you're gonna need if you're using the LSI calculator. If you go to the Arenda app, you can see that it starts off with water temperature, then pH, then you have your total alkalinity numbers, then your calcium hardness, your cyaneric acid level, and then your TDS number or salt, TDS salt, and then you have some other factors that aren't really part of the equation per se. You have, of course, I mentioned chlorine level, free chlorine level, and then you have your phosphate level. So the main parameters for water balancing again are pH, total alkalinity, calcium hardness, temperature, total dissolved solids or TDS, and cyanuric acid. So these are the parameters you're working off of to balance the water so that the water is not corrosive or scale forming. Now, one parameter that you really need to, of course, have in the pool to keep it from getting algae, turning green, getting losing the server's account is a proper chlorine level in the pool. And this is something that Bob Lowry has developed over time because if you look at the charts online, you're gonna see a lot of them saying the ideal chlorine level is one part per million to three parts per million. Some charts will say three parts per million to five parts a million, but most of them have the three parts per million as their standard chlorine level. And believe me, this has been an industry industry standard for as long as I've been doing pool service. And this actually is a thing that's gonna get you into a lot of trouble in your pool service or the ability to care for the pool. If you're strictly sticking with the three parts per million or free chlorine, I gotta tell you that you're probably not going to be able to keep the pools from forming algae and staying blue all summer long. Bob Lowry has really come up with this formula to make sense out of a lot of problems we're having out there. For instance, you may have a pool on your route where the chlorine level is at 10 parts per million, but you're still getting mustard algae, you're still getting you're still getting cloudy water, you have really a lot of issues with balancing and keeping the chlorine in that pool. And that's because one thing that Bob Lowry has developed over time in his teaching is that there is a direct relationship with the amount of free chlorine in the pool or the level you keep it at and the level of the cyaneric acid in the pool water. I did mention that you can keep your cyaneric acid level at 100 parts per million, and Bob Lowry has a formula that your free chlorine should be 7.5% of your cyanuric acid level. Now, if you're using borates or another enhancer in the pool like Pool RX, I would say that you can keep your free chlorine level at 5% in that formula versus 7.5% because the enhancer really helps the chlorine last longer in the pool and it makes it more effective. But let's just go off with the 7.5% formula. Let's just say your cyaneric acid level is 100 parts per million. So 7.5% of that would be a free chlorine level of 7.5 parts per million, or let's just say 8 parts per million to make it simple. So if you're maintaining a pool at 5 parts per million and the cyaneric acid level is 100 parts per million, you're actually under that formula by close to 3 parts per million, which means that the chlorine, according to Bob Lowry's teaching, is not highly effective when it drops below that 7.5% of free chlorine to cyaneric acid, which means that five parts per million that pool can still form algae. The chlorine may not kill viruses, bacteria rapidly, and the water quality may suffer, even though you have a chlorine level two parts per million above the three parts per million ideal chlorine range. And that's because the cyaneric acid does slow down the chlorine effectiveness, and the formula that he came up with accounts for that. Now it's a really complicated formula, actually, and the 7.5% is just kind of the simplified version of it. And if you follow the hostum material that Tar Terry Arco promotes, that's actually a minimum chlorine level. So keep that in mind that that's a daily minimum chlorine level based on the cyaneric acid level. 50 parts per million is Bob Lowry's target range, and this is why he has that target range, because then you're not needing to keep the fully free chlorine level at what we consider blazing high levels in the industry, and you're wasting a lot of product also when you have it at that level. But if your cyaneric acid level is at 50 parts per million and you use that 7.5% formula, that means that you have to keep a free chlorine level of four parts per million in the pool for the chlorine to be effective. That's a pretty low free chlorine level. It's only one part per million above what they consider the ideal level in the old charts that they're using. So you're not too far from your target there or from maintaining the pool properly. If you keep your target pH, target pH, target cyaneric acid at 50 parts per million, and it makes maintaining the pool much easier. So 100 parts per million, you're gonna have to keep your chlorine level at eight parts per million. When you're at 50 parts per million of cyaneric acid, you just have to keep it at four parts a million. This is a really important aspect of keeping the pool algae-free and keeping the pool water safe. Again, the chlorine is not a parameter for water balancing per se, but it is a parameter that you test for to make sure you're not gonna have algae and you're not gonna have any water quality issues with the pool. One thing that Bob Lowry really promoted is adding borates to the pool, and that's why he actually changed his formula to 5% if you're using borates in the pool. So this is based on a borate level of 50 parts per million in the pool. And if you have the borates at 50 parts per million in the pool, you would just need to use a 5% multiplier. So if the cyaneric acid level is 100 parts per million and you use a 5% multiplier, you would just need 5 parts per million of free chlorine in the pool to make it effective. If it's at 50 parts per million and you're going to do this formula and you do the seven you do the 5%, sorry, that means that you'd have to have a free chlorine level of 2.5 parts per million or the ideal three parts a million that a lot of charts show. And this is why borates are so effective. They're actually what he what we consider an algist, which means that they really prevent algae from actually developing and forming in the pool. It's not an algicide. Now, there was a borate product by BioGuard many years back that was EPA approved as an algicide, but they kind of let that go and they don't really promote it as an algacyte. And unless it's EPA approved as an algacyte, you can't say your product is an algicide. EPA is really strict about that. So borates are not an algicide in any form. They are an algistat, which means that there's a component of it that prevents algae from developing as algae is forming. It disrupts the cell walls from developing, and it's something that prevents it from dividing and multiplying in the pool. So that's one thing that the borate does in the pool and is highly effective. So if algae is not able to form in the pool, that means the chlorine is much more effective in the pool, and that means that the chlorine technically will last longer in the pool, and that's why the formula has been adjusted for the borates in the pool at 50 parts per million. Now the effect at 30 parts per million and 40 parts per million are very similar, but not quite as good as 50 parts per million. That's the sweet spot that Bob Lowry had developed for having a borate level in the pool. The easiest way to add borates to the pool is using boric acid powder, and I get mine from doodadeiesel.com. And there's a whole, of course, slew of podcasts I have on using borates in the pool that you can refer to. But Bob Lowry really was a big proponent of borates in the water, and that's why he adjusted the target range of his formula. That's why he adjusted, I should say, the percentage of the formula from 7.5 to 5% because borates are that effective in the pool. It also is a pH buffer, I should say, before I end here, and it helps keep the pH from rising in the pool rapidly. So there is two a two-fold effect, technically a three-fold effect of borates, because you have a little more sparkle in the water as well, but the borates will prevent algae from forming and also help the pH from rising rapidly since it's a another pH buffer for the pool. So borates serve an important component in pool chemistry. And Bob Lowry again has a lot of material on borates, and of course, I have a lot of material as well on my podcast and YouTube channel on using borates in the pool. And I I highly recommend if you haven't tried it, to use borates, definitely would recommend using them, and it's going to help you balance the water, especially with the chlorine usage and algae, a lot easier on your pool route or your backyard pool. If you're looking for other podcasts, you can of course find those by going to my website, SwimmyPoollearning.com on the pot on the banner. There's a podcast icon. Click on that. There'll be a drop down menu of other podcasts for you to listen to there. And if you're interested in the coaching program that I offer, you can learn more at poolguycoaching.com. Thanks for listening to this podcast. Hope you guys see a week. God bless.