David Watson, a 40-year pool industry veteran in Perth, Australia joins the show to discuss his findings about using carbon dioxide for pH management, and some fascinating discoveries about Total Dissolved Solids (TDS). And he may have had something to do with the arbitrary industry-standard limit of "1500 ppm above tap water" for TDS.
[00:00] - Intro
[01:27] - David's background
[05:38] - Better Understanding CO2
[10:12] - Runaway TA on CO2 Pools
[15:25] - Why CO2 tanks freeze
[19:11] - Total Dissolved Solids (TDS)
[27:17] - What was the TDS limit pre-2005?
[28:28] - Mutual friends with Richard Falk
[32:01] - Closing
Buy David's book on CO2 for pH management in pools: https://davidwatsonpoolconsulting.com/
193. Pool Chemistry Down Under (w/ David Watson)
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Eric Knight: Welcome back, Rule Your Pool listeners. I'm your host, Eric Knight, and this is episode 193 of the Rule Your Pool podcast. And today I've got a special guest from across the world. I mean, literally on the exact opposite side of the globe. He is 12 hours ahead of us. So for him, it's 5:00 in the morning right now. It's 5:00 PM for me on the East Coast. He is in Perth, Australia. David Watson, thank you for joining the show.
David: Eric, I think what you're doing here is absolutely invaluable to the industry. I really appreciate it, and I'm sure all the listeners do, and I'm glad to be here, and hopefully we can clear up a few things today.
Eric Knight: I appreciate that. I'll send you the Venmo we talked about for saying that, and, uh, sure to get you paid off. I'm just kidding. I appreciate you being on the show. And actually, we got connected because of some interesting questions that you had reached out to me about, and we have some mutual friends in common.
And in this episode, we're going to get into your history in the industries, especially in the commercial pool business, and sort of some revolutionary thinking on how to think about things like carbon dioxide. So I am looking forward to this. Again, this is episode 193. Buckle up, because we're doing pool chemistry down under.
[00:01:27] David's background
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Eric Knight: So David, you reached out to me, but you've been in this industry for a very long time. Give us a brief overview of your background so that the listeners have context for why we're even talking and what we're going to bring to the show.
David: All right. Well, I, um, got into the industry in 1986 simply parking in the wrong space. I was actually going for an interview for a carpet shop, and I was running early for the interview. And it was one of those kind of roads that we call light industrial. So there's like panel beaters and carpet shops and, was a pool shop there.
And the pool shop was closed, and I thought because it was a Monday or a Tuesday, that they trade all weekend and closed during the week. So I simply parked in front of the shop in the shade and sat there to read my book 'cause I was running early. About five minutes after I parked, a van belonging to the shop pulled up. jumped out, came over to the, um, car and he said, "Oh, what are you doing here?" And I kind of went, " Well, I'm just reading my book 'cause I'm running early for a job interview over the road." "Oh, oh, we're looking for staff. After you've been to the interview, can you come over and see us?"
What I didn't know was the reason he wasn't there was that a ex-business partner had broken into the shop, had barricaded himself inside the shop. Allister, the guy that had been driving the van, had driven to Tekapuna Police Station, 'cause at that stage of the life we didn't have mobile phones, and had gone to get the police. And of course came back, found me, and thought I was something to do with the break-in.
Eric Knight: Oh my goodness. So let me get this straight.
David: it
Eric Knight: You had no intention of getting into the industry. It was just the wrong place at the right time?
David: Yes, absolutely.
Eric Knight: Wow
David: And forty years later, here we are.
[00:03:09] David's bend for the industry
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Eric Knight: Oh my gosh. Okay, so 40 years ago, wrong place, right time. You get recruited into a pool shop. You got into commercial pools at some point, 'cause in our conversations offline, you've been tinkering a lot. What have you-- Like, what's driving you to stay in the industry, for one? And like, why, why are you always trying to figure out a better way?
David: So, um, when, when I started, I realized that I had a odd bend for this industry. And if ... looking back in, in hindsight, I realized that it was always going to be this industry would call to me. And in that first 10 years or so, I worked in manufacturing, I worked in product development, and I worked in retail. And then I switched countries. And came over to Australia and, and set up in Perth. And in Perth, I looked up the most advanced swimming pool chemistry person I could find, that was, um, Ty Webb. And Ty was the chief scientist at the government chemistry laboratory. And Ty spent his weekends over probably three or four months coming out to see me out at Joondalup, which is, um, about 35Ks out of central Perth.
Eric Knight: Mm-hmm.
David: And he taught me about CO2 gas and Henry's Law and all the things that you're talking about.
Eric Knight: And that was in the '80s?
David: And that was in 1993.
Eric Knight: Okay, so it only took a casual, what, 33 years-ish, uh, for this information to get to me. No, actually, I've been talking about it since 2019, but I didn't find it anywhere. But this was known for a long time. That's exciting. But I need to go back a second. I forgot you're not actually Australian. You're a Kiwi, right?
David: Yes. Originally I'm from Kiwi.
Eric Knight: Right. So he's from New Zealand and then moved over. Okay
David: no, no, no. It was when I came to Perth, I met Ty.
Eric Knight: Mm-hmm.
David: Um, it was because I'd moved countries. I'd been playing with geothermal water, I'd been playing out in the bush um, pools in the bush. And then, um- Yeah ... when I came to Perth, I thought country, water. Even though I'd been in the industry 10 or 12 years by that stage, I thought, "Oh, I need to get some further training."
Eric Knight: Smart
David: that's why Ty,
Eric Knight: Right on
David: Ty talked to me about CO2 due to the natural water bodies. so he introduced me into the mathematics side. Which is detailed in the books that I've written, but it's not easy to explain over, over a podcast.
[00:05:38] Better Understanding CO2
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Eric Knight: Yeah, we don't need to get too deep into that, but you did send me the manuscript for your CO2 book. So maybe go over that, and then let's move into TDS, which is another thing that you've specialized in. So, uh, I've talked to the audience about carbon dioxide being a good proxy for pH because the carbonate buffering system, meaning carbonate alkalinity.
When you put acid in a pool, the hydrogen ion is the acid. It has to go somewhere, and it neutralizes against alkalinity. Therefore, the amount of dissolved CO2 in the water is a really good proxy for determining your pH. Yes, it's about hydrogen concentration, but it's, it's measurable with CO2 as well, and that's why Henry's law takes into effect because, you know, a beer goes flat just like your pool will go flat. So that's what my audience knows about.
You've taken it to a much higher level, especially with commercial injection. You can inject CO2 to lower pH. I think a lot of people know that. But let me just set that as the foundation and just let you talk. What should my audience know about carbon dioxide?
David: Well, what happened was that, um, I, I was tasked in '96 with setting up the commercial pool division within the company that I work. And I was looking for an edge because the market here, you know, we've got one and a half million people now. It was about one million people back then. The commercial market is fairly small, it was very saturated. So I was looking for an edge, a way, a way in. So what I did was I thought about what Ty had taught me about CO2, and I thought, "Oh, I wonder if there's an opportunity there."
So I rang up the, um... I think it was British Gases back then, who were the supplier of carbon dioxide gas, and they told me at that time there was only two pools in Perth that were using CO2 gas. And both of them were complaining about the consumption rate and the runaway total alkalinity problem. So when you inject CO2 into a commercial environment, what is often seen a accumulation of total alkalinity very, very rapidly. So what I did was I phoned up the one that was closest to my house at the time, and I was told that they'd literally pulled the CO2 gas out due to issues and runaway alkalinity that morning.
So I phoned the other pool, and they said, "Well, what? You think you can reduce our consumption?" I said, "Yeah, I think I can." And they went, "Oh, well, what would that cost? What would you need, and when can you do it?" And I said, "Well, I'll just need the pool shut for a few days. I guess it'll cost, I don't know, 3,000 bucks and, um, some chemistry." And, and they basically went, "Okay, I'll give you an order." And that Easter, that following Easter, I spent all Easter at this pool. It had alkalinity when I arrived of over 200 milligrams per liter
Eric Knight: That's parts per million, folks. He's in, he's in a country not called the United States, so he uses the metric system like everybody else in the world. Continue
David: Sorry about that. Um,
Eric Knight: All good
David: so yeah, it was over 200 milligrams per liter. And I added, uh, I can remember quite well, I added a ton of acid. the pool's quite large, so, so it needed liters. Um,
Eric Knight: Oh, you, oh, so you actually added a literal ton of acid?
David: Yeah. Yeah, literally
Eric Knight: Wow.
David: liters.
Eric Knight: That's cool.
David: you know, it's
Eric Knight: That's also a lot of acid
David: It's like a million and a half liters pool.
Eric Knight: Yeah
David: I had to cut the alkalinity down to below the calcium hardness. ' Cause if you drag the calcium hardness past the total alkalinity, the, it forms calcium carbonate. The water goes kind of white, cloudy, kind of rolling, snowing type look. So I dropped the TA below the, um, calcium hardness, built the calcium hardness up. Um, and then within, by Easter Monday, was absolutely crystal clear. And in that first week, I was told the bathing load had increased, not by a little bit, 70%. And their carbon dioxide consumption had dropped by about 60%.
Eric Knight: Do you remember where you lowered your alkalinity to?
David: Not, not now. It's, um, a few years back now . But
Eric Knight: Well
David: probably, probably about 30, 40
Eric Knight: Oh, 30 or 40. So that's actually lower than anything I've recommended. I don't want to ever go below 50, and we recommend aiming for about 60. The American standards say you can go down to 60, and I think that's usually a pretty good number for chlorine pools that are using a hypochlorite. I want to address two things that you just said.
[00:10:12] Runaway TA on CO2 Pools
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Eric Knight: The runaway total alkalinity creates a vicious cycle because the higher your alkalinity, the higher your pH ceiling. And since Henry's Law doesn't care about where you start, it cares about where you equalize. The further you are from that ceiling, the faster your pH rises because you're more carbonated.
It's no different than champagne versus beer. You open champagne because it's more carbonated, and you get this much more violent off-gassing of CO2 to start versus a beer that goes kss. Champagne goes boom. So if I've got a high alkalinity in my pool, the initial off-gas of CO2, which raises my pH, is going to be much faster. And that's what these customers were experiencing. The alkalinity's climbing. I'll get to that in a second. But the pH is climbing really fast, so you have to inject more CO2.
Well, that creates a self-fulfilling prophecy because you are consuming more CO2, but it's just off-gassing faster. And the reason the alkalinity is raising is because the excess hydroxide in the chlorine. The CO2 isn't in-- It's not adding any alkalinity to the water. You're just not using acid to neutralize the hydroxide in whether it's liquid chlorine or cal hypo, and that accumulates, and it accumulates faster and faster and faster the more you use it.
Am I right so far?
David: Yes, that's, that's effectively everything that incorrectly cited as being caused by CO2. So, so it's definitely the hydroxide that's causing that issue.
Eric Knight: Cool. Then I'm just going to quit while I'm ahead and let you continue talking
David: It took me a while to work that out. Ty had taught me about CO2 and about CO2 content and with atmosphere and so on. However he hadn't discussed this, this issue because frankly, I don't think he knew that. But it took me a while and I worked that out and, and that's further detailed. So in, in the books, I go through how to inject the CO2 correctly, how to set it up correctly. So for, you know, larger processing systems, um, 'cause most of the systems I'm working on, talk about liters per second. So we're talking about 50 liter per second systems, uh, which should be about 10 gallons second, I guess, roughly 10,
Eric Knight: h-how many liters per second?
David: gallons, 50 liters per second
Eric Knight: that's fast
David: So, these are large- larger systems. so, so with those larger systems, they're typically an industrial style pump, so it's cast iron, bronze, impellers, stainless steel. So what I do is I inject the CO2 or put the diffuser for the CO2 into the suction side of the pump. What that does is because the gas is very, very minor, in quantity, it diffuses really well. As the pump impeller spins, it gives it the chance to, dissociate into the water really well. So it just dissolves, and you get full dissolve and so it corrects pH. one of the tricks to, to making it last longer.
Eric Knight: Yeah, we've heard of, uh, Venturi feeders like Mazzei injectors or Mazzei injectors. I actually had the guy from Mazzei on this podcast. He corrected the pronunciation. But what we think of as a Venturi suction feed. The issue that I keep hearing with commercial customers is, yeah, we inject a lot of CO2, but like it just doesn't last long. So this is a mechanism that you've found helps it dissolve better, right?
David: Yes. Dissolves better, and by dissolving better you get better pH control. But there is the other side as well, which is you do have to maintain and control your alkalinity with acid. uh, however, you're not using the acid for pH correction anymore. using the acid for TA correction, is all caused by that hydroxide ion.
Eric Knight: Right, from the liquid or cal hypochlorite.
David: Yeah, from your chlorine source.
Eric Knight: So it's interesting. So you're injecting the CO2 on the suction side before the pump and using the physics of the pump intentionally to dissolve it better.
David: Yes
Eric Knight: And what are the results of that compared to, say, injecting on the return side like everybody else does?
David: Quite often what you'll see is if you go to the pool and you just look at the water, uh, particularly the return jet closest to the plant room, what you'll often see is a very slight shimmer of bubbles. And that slight shimmer of bubbles is literally CO2 gas being pumped out directly into atmosphere. Um,
Eric Knight: So wasted
David: Yeah, you want to avoid that. Um, you can also see it sometimes, or you may not see it, but you'll hear it in your filter 'cause most of the filters or sand filters have an external air release or vacuum air release, and you'll hear it hissing as, as the gas comes off.
Eric Knight: What kind of installation is required for a suction side? Like, is there a check valve involved? Is it just a sheer injection based on CO2 tank pressure? How do you actually inject it?
David: Normally it's just a tank pressure through a... 'Cause usually we're using, we're using ceramic diffusers, so the ceramic's effectively a check valve in itself. By its sheer density, it's hard to push through from water pressure, but the gas pressure's higher, so it pushes through. And that's been the method that I've found to work really well. I've got a couple of other methods, but that one works very well.
Eric Knight: Okay, cool. And because it's the suction side, water's not actively trying to push up that hose like it might be on the pressure side?
[00:15:25] Why CO2 tanks freeze
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David: That's right. It's trying to suck the gas through, which helps with the gas itself trans- through. It does from time to time, um, and I think this is true for all CO2 installs, um, do from time to time freeze up, but that's a relatively simple fix. Um, it's usually across the solenoid, and you literally just heat it up with a heat gun to get rid of the ice and you're done.
Eric Knight: Well, I've always wondered that because that's one of the complaints that my customers have had, that they use CO2 and yeah, it freezes up. You get literally a block of ice on the one that's being used. Why is that happening?
David: It's the Joule Thompson, I think it's called, effect. it's basically the gas is going through the tube or the fitting too fast, you're getting a pressure change, and that causes this freezing. It's fairly easy to fix with a heat gun to remove the ice. The challenge with the ice is that it can actually ice up and hold the valves open, so you end up literally dumping gas into the pool.
Eric Knight: And how do you prevent it, or can it be prevented?
David: Um, it's a management thing. It's a combination that needs to be just balanced. It's a balance of both, um, demand and gas pressure, and tube size. There's quite a bit to it
Eric Knight: Mm-hmm. Right on. And, and in your book, do you discuss that so that an operator who buys your book can learn how they should be sizing their system so they can avoid the icing problem?
David: Everything is covered in my book. I have decided five years or so ago I was going to sit down and document all these things that I've worked out over time that others could learn from it and grow with it, and hopefully take it to the next level.
Eric Knight: Right on. And is it published yet? 'Cause you sent me the manuscript.
David: I've just literally this morning got it back from, um, the layout art people,
Eric Knight: Mm-hmm.
David: so I'm expecting it out in a couple of weeks' time
Eric Knight: Right on. What is it going to be called and how can people find it?
David: One way to find it is through my website, which is davidwatsonpoolconsulting.com. It's called CO2 for pH control.
Eric Knight: Mm-hmm.
David: Um, it's fairly straightforward,
Eric Knight: And I will put a link in the show notes, which Jarred never reads. But I will put a link in the show notes for those of you listening on your phone. You can tap that hyperlink and get that book, 'cause I did read the manuscript to it, and there's a lot in there that I did not know, so I'm excited about that.
I want to move forward, since you've been in the, in the trade for a while. Uh, once you have the final say on CO2, is there anything else you would like the audience to know?
David: I think so. And for a commercial environment, is actually a really good choice. It gets out of a lot of dangerous goods handling. And I am an ex-accredited dangerous goods consultant in Western Australia. Some of that is covered in that CO2 book. It's also covered in some of the others, um, in more detail. It's a interesting chemical, it's useful, and it definitely serves a function. The thing that I like most with it is that even in the case of a complete malfunction, the pH is unlikely to go below six point one, which makes recovery fairly easy.
Eric Knight: Yeah, I should say. Do you see the dog behind me? Are you trying to get involved? This is our Great Dane, Emmy. And Emmy likes to get involved in the podcast. So those of you listening to this, there's a giant, giant sweet girl right behind me. Can, can I continue? She does, she does look great. She's a good-looking dog.
Anyway, thank you, Emmy. I appreciate it. Uh, so
David: of that
Eric Knight: yeah, no, she's a big, she's a big girl. Yeah. She's about 70 kilos
David: Yeah, ours is about three.
Eric Knight: Yeah, a big difference. Uh, that's, uh,
David: just a bit
Eric Knight: Right, right around 140, 150 pounds, so for my American listeners, all 17 of them.
[00:19:11] Total Dissolved Solids (TDS)z
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Eric Knight: So, um, you were talking to me back and forth in email about total dissolved solids, and you actually referenced, because I said it in several podcasts, that I still have no idea why our standards say you shouldn't have more than 1,500 parts per million or milligrams per liter above the source water for total dissolved solids.
And you said, "I think I know how that came about." So total dissolved solids, what do you know or, and is this rumor? Is it verified? I don't really care. I just, as long as it's specified. Give me the tea. Spill the juice. Here we go.
David: I'm just going to tell your listeners the story I told you. I don't know how much is true, how much is story.
Eric Knight: Oh, I love these. I love these. That's the disclaimer.
David: you
Eric Knight: Let's just listen and enjoy this.
David: I'll
Eric Knight: for it
David: what actually happened. So as we mentioned earlier, I'm originally from Kiwiland. and, uh, when I started in the industry, as you probably rightly know, there was very little in the way of education and information. So I wanted to learn more. So what I did was I subscribed to every pool magazine I could find around the world, and I did do some studies with the Institute of Swimming Pool Engineers from the UK, for the first year or so, but I couldn't afford at the time to go and do the exam, which I had to go to England to do. And amongst all this reading, I read that there was an international limit to total dissolved solids, and at the time, it's some time ago, I think it was 1150 or 1350. It was somewhere around there.
And indeed, in New Zealand, what would happen is that I would see these pools coming in with this, their water samples, as you do at a pool store, and invariably, if the TDS was at 1150 or 1350, whichever it was at the time, or above that, quite often the pool would be green and very difficult to get clear. And the only way at the time to fix it was to drain and refill.
Come forward to Perth. So that was the experience there. In Perth, I found the opposite. I found pools here quite often with TDSs and, you know, 2000, 3000, 4000 range. We'll leave salt pools for now. So then in about 2005, 2006, the Department of Health rang me and asking me, "What do we do about total dissolved solids in our standard, our code?" We've got... Originally, we had 1,500 as the maximum limit. But our tap water is quite often 600 or so in Perth due to the chlorides content in our water. And I said, "Well, I don't know." I, I said, "You know, when I started, I was taught this international limit. Then I came to Perth, I discovered this." Um, you know, "Yeah, but we've got to have a limit. We've got to have a limit." I guess what we do is we make it 1,500 milligrams per liter above the incoming supply."
Eric Knight: This was the health department?
David: Yeah. So that then became, got written into the code of practice. So, so our code of practice here is like our rule book, like the MAHC.
Eric Knight: Right
David: Um, it's very, very similar. that was back in 2005, 2006. The code was enforced in 2007, uh, gazetted they call it here. So it became effectively law. I'm told by the department that they sent that to the American authorities, and I'm not sure who that was, the CDC or whoever it is. And our health department claims that our code is the basis on which the MAHC was written. don't know how true that is, but it's just a story they say, which makes you wonder, is my casual conversation, "Well, I guess we've got to do this," become enshrined in the American code as well?
Eric Knight: If you were responsible for this 1,500 milligram per liter, heh, limit of TDS over tap water, David,
David: Mm-hmm.
Eric Knight: off my Christmas card list. I will tell you, I've been so frustrated with this, and no one's ever explained it. But I would love to believe that you had something to do with it, in all seriousness, because it has always seemed so arbitrary.
Two questions. Back in that day when you were still in New Zealand, the pools that were turning green and needed to be drained and diluted because the, it probably wasn't the TDS, but there was something going on. Were salt systems common in New Zealand at the time?
David: No. This was all pre-salt.
Eric Knight: Ah, okay
David: all either, typically they'd be, uh, ticker tab- uh, trichloro tabs, you know, I think you guys call them pucks.
Eric Knight: Yeah, trichlor. Trichlor pucks, yeah
David: And, um, we didn't them through winter, so it wasn't cyanuric acid build up, 'cause you get enough rain there to dilute the cyanuric.
Eric Knight: Mm-hmm.
David: Um, but if they, they were either running, uh, trichlor or occasionally cal hypo
Eric Knight: Interesting. So it wasn't necessarily the TDS that was causing it to be green, but I think a lot of things in this industry, there's a problem, let's see if we can figure out what it is. And sometimes without doing the due diligence to isolate a single fix, you don't actually know what fixed it. Like if I do four things to try, try to address the green pool, I don't have time to wait and figure out like exactly which of those four it was that did it or maybe these two of the four.
We just threw everything and hoped that something stuck. And I think that's how our industry has gone for so long that, well, it ha- it had to be the TDS. TDS had to be something to do with those pools turning green.
But what if it was cyanuric? What if it was ineffective chlorine? Or what if it was, you know, some contaminant that's not being aware of, or, or maybe there was organic loading that you couldn't get out and it was gumming up the filter? Or maybe it was biofilms?
We don't know. That was 30, 40 years ago. And yet we are still dealing with a 1,500 part per million over tap water limit. Which to me is hilarious because you don't control the tap water. And w- it's just okay if I have 600 versus 200? That's a difference of 400. That's a pretty big percentage difference on TDS if it was really that big.
And what I've always said about TDS is it's not so much the amount of TDS, it's what is the TDS? If it's high cyanuric, that's a problem. If it's too much calcium that you can't maintain LSI balance, that's also a problem. But I mean, we've had pools well over 6,000 and 7,000 TDS that look great. They're fine because they don't have too much CYA.
They don't have too much calcium. It's just chlorides that build up over time. And sure, eventually it can become problematic. But, um, it's good to know that this was pre-salt. What do you think--
This is my second question. What do you think was different about Perth when you moved over there that you were starting to see 3,000, 4,000, 5,000 TDS and they were not having issues? What was the difference between New Zealand and Perth, do you think?
David: Um, I think it's actually fairly significant. Now, I have written an article, which I think is going to be published in Aqua Magazine in, um, July, August edition on TDS. But, in a nutshell, if you contrast the two environments. So New Zealand's environment, I'd call it, um, subtropical rainforest. So it's fairly heavy with bush, it's heavy with rain. You've got a lot of nutrients flying around. And in contrast, the Perth environment is Mediterranean,
Eric Knight: Hmm.
David: or very Mediterranean. So, so it's very dry. Um, it's actually desert state. It's fairly high, uh, chlorides, whereas in Per- in Auckland, the chlorides aren't anywhere near as high.
Eric Knight: Chlorides-- Hold on. Chlorides in tap water, you mean?
David: Yes.
Yeah,
Eric Knight: Okay
David: I was just going to say that if, if we look at the two tap waters, in Auckland, you would be struggling to see 100 milligrams per liter total dissolved solids out of the tap. Perth, in-- I won't go into all of it, but 600's not unusual. So they're very different waters. Um, so, so the two, countries, the distinction is so different, I think that's, that's really what we're seeing is in one we're seeing a buildup of nutrients, and in the other not. We're seeing a buildup of chlorides.
[00:27:17] What was the TDS limit pre-2005?
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Eric Knight: Right. And so this conversation you had with the health department back in Australia, uh, what years did you say this was? 2006-ish?
David: 2006, somewhere in there
Eric Knight: So I, I don't, I'm, I'm sure some listeners here have been in the industry long before that. I was not. I was in college at the time. But, um, I'm sure if we go back to what was said prior to that, some people probably still have books from back then.
It'd be interesting to see what the TDS recommendations were. Listeners out there, please, if you can find this for me, that'd save me a lot of headache. Uh, just email me, ruleyourpool@gmail.com. I would love to know what this is. See what the TDS recommendations were pre-2005. And let's see if David had any hand in this, 'cause it's this, this nonsense has been getting me so, so confused.
I'm scratching my head, and I'm losing hair because of it. No, I'm just kidding. It, it's not that big of a deal. Honestly, I hardly ever think about it. But, um, I do want to keep moving forward. Is there anything else you'd like to talk about with TDS?
David: Um, honestly, if you stay in this industry long enough, you definitely lose your hair
Eric Knight: Yeah. Well, that's why I'm wearing a hat, you know? As a new, as a new father, I'm starting to realize what not sleeping much at night is. Although my baby is sleeping through the night, so we're doing well there.
[00:28:28] Mutual Friends with Richard Falk
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Eric Knight: Um, so you, originally through some online forums it sound like, we have a mutual friend in Richard Falk. Tell me about that.
David: Yeah, so, um, originally it was through the online forums that I started to chat and realized that here's this guy who's talking about stuff, and, there's actually a funny story to that. That I understand really well. But he's talking about it at a depth that I don't understand, if that sort of makes sense.
Eric Knight: Oh, w- with Richard, that's exactly what happens every single time. I understand it completely.
David: So, so the funny story is that the reason that Richard got into this swimming pool industry, was because of trichloro tabs originally. Overdosing his pool with cyanuric. And the odd thing is that if he'd been my customer back in, 1987 even, I would've been telling him to pull the trichloro tabs out when his cyanuric hit about 60 or 70, to stop his pool going into what we would've called back then chlorine lock.
So that's kind of interesting. yeah, Richard, um, and I started chatting on and off the forums. He sent me some background information on ORP and pH controllers back then, um, life happened. And for about 10, 12 years we didn't talk. And then I wrote my first draft of the CO2 book, and I thought, "Who can I get to edit and check it?" So I just reached out to Richard, and he very generously gave up his time and gave me a lot of help around the chemistry stuff, 'cause chemistry is not my strongest suite. Uh, you may think differently, and I understand why that is. I'm a systems guy, not a chemistry guy. I think in broadly in systems rather than the chemistry.
So Richard helps me a lot. I reached out originally over the CO2 book, and then I had another odd sick happenstance, um, in a bromine spa. And concerned with that, I reached out to Richard over that specific incident to see if my thinking, which is systems-based, was correct. And how we could fix it.
And between that collaboration plus stuff I'd written in the CO2 book and some other things, we ended up designing a alternative dosing system, which we call the Falk Watson method, for controlling the pH within a water environment. When it's recirculating.
Eric Knight: So can you outline just the, just the touch points on what is the Falk Watson method, if you could summarize it?
David: It's basically a method whereby we change the way the injection occurs to stabilize pH, and that's subject to patent and confidentiality agreements and things, 'cause I'm in discussion with manufacturers at the moment.
Eric Knight: Excellent. Well, that's exciting. I think the technology in our industry has advanced quite a bit, and every now and again, there's a product that comes out that just works extremely well, and they are usually very simple. Like, the kind of products where you're like, "Oh, why didn't I think of that?"
And that sounds like what this might be, and, uh, don't, don't give it away, but I'm excited to learn more about it when all that's ready to go. Is there anything that you want our listeners to know about it?
David: No, I think that's... At, at this stage, that's all I can say. It's still subject to confidentiality.
Eric Knight: Good. Keep them guessing. I like that. Good.
David: yeah. One- once
[00:32:01] Closing
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Eric Knight: how about this? We've been speaking here for almost 40 minutes. I am so grateful for your time, and you got up so early for this, which is just amazing. So thank you for that. And I hope the listeners find this valuable. I know I do. I've learned a lot about CO2 from you and your manuscript of your book. So again, listeners, I will be putting the link to buy that book in the show notes, or at least to go to his website. Uh, but you've been boots on the ground with a lot of swimming pools. So use this time now to speak your mind. Is there anything else you want to say to me or the audience?
David: Yeah, there is. I've been doing this for forty years. And thirty of those, in fact, more than thirty of those years, I've been dealing with health departments, regulators, and so on. What I've noticed and what I've learned is the regulator not against you. They're not there to stop you. In fact, if you can show them how you can do something within the regulation and within the framework they can approve it, they will, and they actually want to. So a lot of people have the opposite idea. Your health department people are not your enemy. They simply need things done a specific way to make the things safe for health, for the health and welfare of the bathers. Start from there.
Don't start, "They're my enemy." They're trying to work with you to make the environment safe and make sure everyone is healthy. That's my main message
Eric Knight: Well, that's good feedback. I know quite a few health inspectors in my line of work. Uh, well, honestly, my key interaction with health inspectors has been getting phone calls from them asking me what am I teaching these pool operators and why are they, you know, saying that they can-- why are they saying that they can have a higher pH on an outdoor pool and having to explain myself.
But in every single conversation I've had, except for one, and I still remember that guy, but, uh, every single one of them when I explained it, they were like, "Oh, I had no idea." And then they get it. Now, it doesn't mean that they can make ultimate exceptions for every single person, especially in a commercial pool, but at least they understand the premise of why we're saying, "Hey, you can slow the rise in pH by having lower alkalinity.
You can feed acid, or in this case, CO2, less frequently throughout the day and save a lot of money on those chemicals," whether it's CO2 or acid, and bicarb, by the way. You can do these things. You can do it a different way. You don't have to be between 80-120 on alkalinity. You just don't.
Maybe with tabs you want to be 80-90 probably. But 120? Especially on a salt pool, liquid chlorine pool, or cal-hypo pool? 120 mg/L or part per million alkalinity is over-carbonating your water. That's my opinion, but it's backed up in real science, and it's going to raise your pH quite quickly.
And if, you know, if you like spending money on, on all these chemicals, that's fine. Good for you. But for the rest of us, there's this method, and I can't wait to see what the Falk Watson method does for CO2. It sounds to me, based on what I've read and based on what we've talked about offline, I think it's going to change how CO2 is injected in our industry, and hopefully it affects change in the United States, because there's a lot of commercial pools here that could really use some chemical savings. For some reason, costs just keep going up, so it'd be really good to find some savings.
David: That's what I'm setting out to do
Eric Knight: Well, you are in Perth, Australia. It is 5:45 in the morning. It's 5:45 PM, and I am smelling dinner at the moment. My wife is cooking a wonderful dinner, and I have enjoyed this thoroughly. David, thank you so much for joining The Rule Your Pool podcast and for reaching out, introducing yourself, and teaching me a different perspective on how things are done.
And I really hope a listener can chime in with regulations on TDS, or, uh, you know what I mean, standards on TDS prior to 2005 to see if there's any validity to what David said. Which I think there is, but who knows? It ... Was he the first one to do it, or was he just a, a more recent one? I don't know. I think it's exciting either way if we can finally come down to some answers. Because if it was different before 2005, David, the 1,500 parts per million over tap water, uh, standard was just a suggestion. I love that. I absolutely love that
David: It was no more than that. That's all it ever was.
Eric Knight: Well, I think there's quite a few standards that were like that, to be honest with you. And I know those people listening to this podcast who write those standards really love when I say that. So yep, thanks for listening, all. This has been episode 193 of the Rule Your Pool podcast. David Watson, thank you so much for joining from across the world. It's amazing that we live in an era of technology that we can do this. So thanks again
David: Thanks very much, Eric. a good day or
Eric Knight: All, all right. Uh, uh, it's a nighttime for me, but have a good day.
David: All right.
Eric Knight: Thank you
David: See you, man.