Salt

In the conclusion of our conversation with Lee Moore and Blake, Technical Director at AIS Water, we examine what it takes to make saltwater chlorination work reliably in demanding commercial environments.

Commercial pools cannot be managed by reacting to every change with another drum of chemicals. Like steering a cruise ship, water chemistry requires calculated adjustments, accurate information, and equipment sized for the facility’s actual operating conditions.

The conversation covers the difference between ORP and direct free-available-chlorine measurement, on/off versus proportional chlorinator control, and how properly sized systems respond to sudden increases in bather load. Lee and Blake also explain why some facilities retain liquid or granular chlorine as backup sanitation—even when onsite chlorine generation handles nearly the entire demand.

We also challenge some persistent assumptions about saltwater pools. Modern commercial systems can operate at salt concentrations as low as approximately 950 ppm, opening the door for indoor pools, facilities with natural stone, and other applications where corrosion concerns have discouraged saltwater chlorination.

Finally, we look behind the marketing of “mineral pools.” Magnesium and potassium salts may change how the water feels, but the sanitation still comes from chlorine produced through electrolysis. Minerals do not replace the sanitizer.

Topics discussed include:

•  Why commercial chlorination begins with accurate system sizing 
•  Accounting for sunlight, bather load, turnover, and unusual applications 
•  Why water stability is more important than constant chemical correction 
•  Direct free-chlorine probes versus traditional ORP control 
•  On/off and proportional 4–20 mA chlorinator control 
•  Responding automatically to sudden increases in bather load 
•  Cell operation, reversing cycles, and expected service life 
•  Using liquid or granular chlorine as secondary sanitation 
•  Reducing chemical handling without removing backup infrastructure 
•  Liquid chlorine degradation, declining strength, and chlorate concerns 
•  Commercial chlorination at approximately 950 ppm salt 
•  Saltwater systems for indoor pools and natural-stone environments 
•  What “mineral pool” marketing gets right—and what it leaves out 
•  The roles of magnesium and potassium in swimmer comfort and water appearance 
•  Why mineral pools are still chlorine pools 

If you operate, specify, design, or service commercial aquatic facilities, this episode offers a practical look at building a chlorination system around stability, predictable demand, and intelligent control—not chemical firefighting.

Transcript

SPEAKER_00 0:53

Welcome back to the conclusion of our talk on commercial saltwater chlorination with AIS Waters Lee Moore and Technical Director Blake. We join this conversation in progress. The building was so large they cast a shadow for about 80% of the day. I think they had three hours of sunlight in the morning and then it was in a per perpetual sh uh shadow the rest of the day. So we we took that into account because we knew that the chlorine wasn't being uh destroyed by UV because it was in the shadow of the building most of the day. So interesting. We take all that in of virtually every site that we that we go to. We we we ensure that that sizing's done correctly because the the last thing we want is to have a system that is too large for the site because that's wasted capital, and then we don't want a system that struggles to keep up. And then we get the curveballs. How much chlorine does a seal take? What about a what about a horse? What do they do? We've done a few horse pools. Yeah, how much chlorine does a horse take when it gets dipped and goes into a training side. Any circumstance or water body? Any any any body of water that needs to be kept beautiful is potential. We were we were actually even uh Googling the reflection pool, weren't we, Lee, when all that started. Just thinking, hmm, I know how to solve that problem. We've seen that before. We've seen that in pools where they're dosing chemicals that are probably interacting with each other and causing issues. So stability, water stability is the key to that. Keeping things as stable as possible is the key to keeping that water healthy. Pouring in drums and drums and drums of chemicals is just it's never the way to go.

SPEAKER_02 2:39

Yay. I travel round the suburbs, test kit in my hand. Lee from the pool shop, coach, she's the best in the land. Nick from Brisbane called me to make the PH wild. Got the skimmer in the neck, gonna make the pool.

SPEAKER_01 4:26

So if you're in respect, go anywhere out. Collie and Lou. Best in town land down. We clean pool.

SPEAKER_00 4:54

Pouring in drums and drums and drums of chemicals is just it's never the way to go. Pools can't be treated in a reactive way. You can't just ship things instantly. I I've actually used cruise ships for a really long time as a bit of an analogy of swimming pools. You can't turn a cruise ship on a dime. You've got to make calculated adjustments and move very gently, same as pools. If your pH is off, if your ORP is off, you can't instantly change that. You need to come up with a plan and slowly make those changes. If you just your pH is 7.9 and you need to get down to 7.4, there's no way you can go and dump 40 liters of acid directly into that pool. It has a knock-on effect. So you've got to just slowly chip away at it to get it back within range. If you make those quick, sharp decisions, those sharp changes, it's going to throw something else off. So that's the one of the big benefits of the of inline chlorination is it does keep that stability. It keeps things stable and it keeps everything uh balanced. And it's the the the biggest change that people um recognize when they when they convert. It's always that stability of that water is the first thing. There's there's not as much smell, they don't get itchy, they don't get irritated. Um the the water just looks and feels healthy. It feels alive, it's got that sparkle to it. That's the biggest thing that we get when we when we do a conversion. Because previously, you know, not quite as bad as the cruise ships where you can't see the bottom, but you know, some of these pools aren't aren't that far off. When you come when you go up to a pool that um that's neat needing a bit of help and you can't see the lines at the bottom of the pool, you know that there's it's it's well there's um there's multiple methods of controlling everything everything stems so in in that respect, everything stems from the probe. So the first step is to get a very high quality probe and the the new FAC probe's coming out probably only in the last few years, it leaps and bounds. So getting a the right probe is of course the number one, and then from there, once you have a good gauge of the chlorine in the pool and it's an accurate gauge of where the pool is actually sitting, free free available chlorine. Yes, so there's two ORP spot on. So the ORP has been widely used for a very, very long time. But I've always said to people, ORP is more of a I don't want to use guesswork, but it's a it's a it's an indicator. Well, it's not a precisely but then when you're trying to keep it between two and four, it can be a bit tricky and people don't quite get that calculation and they they think the ORP is good, but they don't check the free chlorine and then things are out of spec and they it gets lost. So then you're losing absolutely completely so um so getting the right probe installed, number one, that's accurate, and then from there there's two ways of controlling the chlorinator. The most popular is just a simple on-off. So that's as soon as a set point drops down, although the the chlorine levels drop and away from set point, it'll tell the chlorinator to turn on. The system will start generation at a set output, and then once it achieves set point, it'll turn off. The other way is a bit more responsive to beta loads, and that's called the proportional 4 to 20 milliamp. So at set point, it's sitting on standby, but then when it starts to move, the further away from set point, the higher the output of the chlorinator. So if the set point is say 3.5 and your chlorine is at 3.3, the chlorinators are sitting at about a 20% output, just just hovering along, just keeping that residual chlorine in the pool. You get a school load full of kids come in and jump in that pool all at once, that free chlorine will start to drop down. And then as soon as it starts to drop down, conversely, the chlorinator will start ramping up. So it's it's an instant change to the chlorine levels. So it will ramp up according to that beta load. It'll respond very, very quickly. And because we take great pride in that calculation, that sizing, we will know roughly how many people will be entering into that pool, what the maximum beta load is for that pool, and we'll have a system that is catering to that maximum beta load. So if we have the right capacity system, then as it ramps up to 100 at 100%, it's got enough chlorine to counteract that beta load, that instantaneous beta load. So it all just comes down to the turnover of the pool and how quickly it can respond. But that would be irregardless of our system or a liquid or granular system, it would the turnover would still be in effect, but we are sizing our system for that maximum beta load, and then you've got the probe automatically adjusting our output depending on that beta load coming in. So it responds extremely well, keeps things very, very stable. It does have an impact. It's not the biggest impact. So it's not going to have. We have done quite a few studies on the impact of it running at 20% to 100% or just leaving it off. So that's why predominantly the on-off is a bit more favorable, simply because any time the system's generating, uh, as Lee mentioned before, the the that ruthenium is a consumable, so it is wearing down. Uh, but we're talking, you know, weeks and months of life here. We're not talking years. So it does have an impact, but it's just that balance of of what you're what risk you're happy to accept and knowing the lifespan and how it's affected. Every time it's running, it goes through that reversing cycle and it's it's slowly wearing down. But in the end of the day, it will still balance out to that roughly 16, maybe 14 to 16 hours out of that given 24-hour day. It'll still roughly be in that zone anyway. So it doesn't have that that big of an impact. Correct. Yeah, just some form of backup system. That of it's a bit of a balance there. So the that some sites have have purposely designed the system, not as a standalone. So it doesn't take the load at 100%, it doesn't completely eliminate the liquid chlorine. We've designed it in a way that the liquid chlorine actually helps supplement the system. So they're not removing infrastructure, um, they're keeping everything as is, but the goal was to reduce their liquid bill by more than 90%. So they wanted to keep the liquid in because that there was a perceived risk. So this is actually in an in uh in an international site. There was a perceived risk of the of the chlorinator. So they said, well, let's design this way, but if we can get 90% reduction, because it was one of those sites that were manually handling drums of chlorine down a flight of stairs, if we can get away with that, uh, that we only have to do that maybe once or twice a fortnight instead of three or four times a day, then this project is a is a huge success. It's always that balance with liquid chlorine. Uh, and I don't typically uh I I don't typically support the liquid chlorine just because we all know that it has a very precise uh shelf life. You don't want liquid chlorine sitting around for too long, a matter of matter of weeks, and then it starts to degrade, and then more and more research coming out that that degrading liquid chlorine is is not very good. There's some some pretty interesting uh studies coming out about the chlorates that are being uh that are being formed in that chlorine going off. So after a after a few weeks, you're wanting to use that chlorine and keep it fresh, and the efficacy, of course, goes goes down. So it should be at 12%, but it gets delivered at 10. And then by the time you're actually using it, the end of the cycle, it could be down to as low as five or six. But we don't want that sitting around for too long. So the system was designed that in the peak summer in peak batherload, our system would take care of 90%, and then just during that little bit, the liquid system would dose in. It was specifically sized that way uh that the liquid would kick in because they wanted to keep that liquid system as a as a backup. In the other sites, that was the only site that ever used liquid. The other sites have all used granular chlorine, where they've had a system because you are correct, in uh in WA, it is part of legislation that a chlorine generator has a second form of primary disinfection. So that can be as simple as uh a granular, granular dosing system or even an erosion feeder. It could be anything. So in that case, if the system we it's normally designed that the chlorinator takes 100% of the load and it's it's always on, it's always working. But in the event that uh the cells finish their lifespan, so after the average of six and a half years, seven years, the cell requires replacement. There could be a couple of weeks there where the chlorinator's offline. If we don't have that preventative maintenance and it's a bit of a no one new kind of scenario, then it takes us about five, six days to make the cell and then have it shipped out. So there is a risk of the system going offline for a little while, and then they have the lick the backup system to kick in just to supplement for those that short amount of time while the chlorinate is offline. If it's a design with intent, it changes everything. So if everyone knows that's the design, everyone's happy. So that's when I it's it's great because the liquid chlorine is three times saltier than seawater. So a lot of people don't know that. That the the liquid chlorine is made from electrolysis. That's how they make it. And they have a brine solution, which is fully saturated salt, uh, not quite liquid salt, but fully saturated salt that goes through electrolysis process, and that's the way they they create the the liquid chlorine. So the byproduct of liquid chlorine is salt. So when you have a system that's got a salt as a bit of a supplementary, that's actually helping us as a liquid secondary, sorry, that's helping us because the byproduct of that is putting salt into the pool, which helps the chlorinator. So it's a nice little synergy, nice little yeah, it works quite well. But the the key risk, and I what I always tell people is just to make sure that that chlorine does not sit round for a long period of time. The last thing we want is to have a delivery of of liquid and then have it sit there for three months. Uh yeah, absolutely. Yeah, yeah. Early October we'll be there again. Um it's probably about our fifth or sixth year in a row we've been we've been going in and slowly chipping away. I guess the head not the hesitation, but it is a learning curve. It is a new thing. Um, and that's probably the biggest thing. The biggest challenge is is getting that education and and prov presenting the technology that is designed to help with that that uh those issues, those myths. So, you know, a lot of people don't realize that you can have a commercial grade system that is running at 950 parts per million. So the the indoor pools, the natural stones, all those concerns around salt water is no longer a concern. And that's just because they haven't seen that technology. That it just simply doesn't exist in certain markets. So it is that education piece, and that's why we love traveling, we love meeting new people, um, talking to specifiers and engineers about this solution, about this technology, because once once they get the the the understanding and so and sometimes it's the simplicity of it all, it's just oh, it's it's still and there's some people get saltwater chloration, they understand the basics of it, but they just they think that it can't work in those lower levels. So once we go through the technology and go through some case studies and you know peek behind the curtains a little bit, once they get that understanding, it's it's just a bit of a revelation for them. So yeah, we we we love sharing sharing the word, so definitely, definitely excited. It also helps that it's in Las Vegas, so that's always a fun place to visit. And I don't mind going there every now and then. So absolutely minerals really took off. Lee, I would say about 10 years ago here in Australia. It's always it's been around for a long time, but it really just took off to the point where people were making specific technology labelled as mineral, where we've been saying, yes, you know, any chlorinator can work. Mineral minerals is still salt. Salt is salt, so it's just a different type of salt that's being used, but it still is a chlorine pool. Still using chlorine. Chlorine's being made by electrolysis. It's still the same thing. Because we we get that a lot. People want mineral pools, but they think it's the minerals that are doing the sanitation. And it's like, not quite. That's very good marketing, but here's here's the education to see to tell you exactly what's going on there. And I've been I've been supplementing with minerals for a really long time. I actually thoroughly enjoy it, and so do the kids. So they you do actually feel the difference because the magnesium and potassium don't react with our taste buds the same as uh as traditional pool salt. So even at the slightly higher levels, it still doesn't quite taste as salty, and just your hair, your skin, everything just feels a lot nicer when you've got that little bit of a mag little bit of magnesium in in the pool as well. The minerals do go a long way. And I've found personally found that the magnesium also has a flock effect. So the pool just looks bluer and clearer, and it just I I believe it is even bumps up the chlorine levels out of the generator. We don't have too many studies on that, but I personally believe the chlorinator is actually a little bit more effective when you do have those minerals in there. It it seems to produce a little bit more when you have that uh magnesium in in the pool. Is that what's special? Yeah, only through the summer months. But I only supplement through the summer. Anything special in winter, it's it's a water feature. When the kids start swimming in, uh depends on how brave they are. Uh a friend of ours was actually in the pool last week, believe it or not. It's I think the water's sitting about 16 degrees and they went swimming because they were from Melbourne. It was a summer's day for them. They're straight in the pool. It was it was wonderful. We were in in, you know, we were all rugged up for our our Brisbane winter at twenty. Lee, you're the chief of sales and marketing. A few more a few more than ten, yeah. Literally, you're recommended. But it's all when it's all you when it's all you do, you get you get to know you next get to know the science when it's when it's all you do. So thank you.