Ep 51 - LSS and Habitat Design Considerations for Large Living Coral Habitats

[00:00:05] Greetings all, Joe Arlotto here with Dr. Jeff Keefaber. Welcome back to Inflow, the podcast where we discuss all things related to aquatic animal life support. This show is sponsored by Longhorn Organics and MDM. You can learn more about our sponsors by clicking on the sponsors page at inflowlsspodcast.com. I say welcome back because I'm just back from summer vacation.

[00:00:33] We took a little break from Inflow. How's your summer, Dr. Jeff? Hot and humid is my summer and I never quit working. So Joe, I didn't get a vacation this summer. I don't know. Maybe your job is just to vacation all the time. It's so enjoyable. Well, it's a lot of LSS, of course. And so sometimes occasionally I get into the human side of LSS and take a dip in a pool.

[00:01:00] Oh, there you go. Okay. Well, so I'm back. Does LSS stand for lying around safe and secure, Jeffrey? Exactly. That's exactly right, Charles. See now, now you see we have to introduce our guests now, but let me, let's, let's get into this. Okay. We've interviewed a lot of people on this podcast. And I think one of the most prominent messages that we convey is there are many aspects of LSS.

[00:01:29] Yes. And many, there's a lot of diversity in aquarium and zoo work. You know, some LSS operators focus more on controls or maybe some on pumps or water chemistry. And then the husbandry folks might deal more with marine mammals or fish or sharks or, or jellyfish.

[00:01:48] And you know, all of these take specific water and specific care. And one of these most specialized LSS and care is coral. Coral systems are very unique. And what's your take, Dr. Jeff?

[00:02:03] Yeah. The thing about this for me and, and learning over the years, and I'm still learning about coral systems, but it's the environmental parameters that have to be just right to propagate and grow out and, and provide for the animal husbandry of coral. Yeah. So our guest today, Charles Del Beek from Steinhardt Aquarium. He's a coral expert, Charles. Welcome to inflow.

[00:02:32] Thank you. Glad to be here, Joe and Jeff. I gave you a very, very small intro because number one, I want to get to this information because there's so much to it, but also, I don't know you, you, you, to me, you're a name that I've known for many years because over the years I've either helped design or learned about coral systems, started them up.

[00:03:00] And you're always a name that comes up in relation to, to coral systems and it's sort of your specialty. So how did that happen for you? Where are you from? And, and how did you get into designing and caring for coral systems? Well, I, that's, that could be a very long, I actually have an entire presentation about that, but, uh, so to narrow it down quickly, I mean, I started off as an aquarium hobbyist.

[00:03:28] You know, I kept fishing with my dad when I was eight, nine, 10 years old. And then we started up a saltwater tank at home when I was 12 or 14. And then, you know, I used to go down to the Keys. I'm actually originally from Toronto, Canada. So we would spend a couple of weeks in the Keys every summer and I would learn how to scuba dive and do underwater photography. And I would actually, you know, do some collections down there and bring them all the way back to Toronto and keep them my home aquarium.

[00:03:52] Then about 1986, there was this whole series of articles that came out by George Smith from the Netherlands and Freshwater Marine Aquarium Magazine, also known as FAMA, which was talking about this whole living reef, what they called a mini reef ecosystem. And at that time I was a member of the Aquarium Society of Toronto, Marine Aquarium Society of Toronto, and we brought him in for a presentation.

[00:04:16] And so we all started up reef tanks at that point with live rock, which was very interesting because that had never been done before. And so that kind of led me down that path. But I'd always been interested in marine biology ever since watching Jacques Cousteau on TV. And so did you, did that move you into working for an aquarium?

[00:04:37] It did. So I started writing articles for magazines and my club newsletter. And one of the speakers that we brought up to the, to MAST was Julian Sprung. And that's when I first met him and we became good friends.

[00:04:57] And at that time in the, I would say the late 80s and early 90s, there was very little objective, let's, shall we say, literature about keeping corals and iodax. And it's also to the European literature because I was able to read, understand Dutch because my parents were Dutch. And Charles, regarding the literature, I just had a thought.

[00:05:20] There are what I call the reef enthusiasts, hobbyists set of literature. To their credit, they are the users of technology. And then there's the peer-reviewed scientific journal articles that we can all pick up on. And where do you come down on, on the body of literature with respect to corals?

[00:05:46] Well, I, there's, you know, I think what you're referring to is the gray literature as well as, which is the hobbyist literature and also books and things like that. And then there's the scientific literature. So I have a master's in zoology from the University of Toronto. And so when I wrote my thesis, it was all about reviewing the scientific literature. And I would sit for hours in the, in the university library, flipping through these little paperback listings of all the papers that were published every month.

[00:06:15] And I would specifically look for stuff about coral reefs and corals. And that's how I really got into it. And so when I wrote the first book, The Reef Aquarium, volume one, that's why we really, we relied so heavily on the scientific literature. To back up some of the things that we knew intuitively that was probably going on in our tanks, but I wanted to be able to have a scientific basis for that, not just rely on the gray literature. So you were home. I mean, is this correct?

[00:06:43] You were home with a home aquarium growing corals. Is that true? Yes. Yes. So I, I started that in like 19, my first reef tank, I started in 1988 and, uh, we had kept sea, oaks, saltwater fish and things like that. And I tried a couple of corals without a lot of the success. And there wasn't much really available anyway. You couldn't buy in Toronto a live coral at all.

[00:07:07] You know, I've Joe and Charles, I, I just want to make a comment regarding science and art. But to me as a scientist, I think about where science does its thing. And then you have to have a little bit of art and curiosity and creativity. Charles, what's your comment about that? I mean, is there, there's some art to this, right? Oh, definitely. You know, there's an art to it.

[00:07:36] There's also a, a simpatico that you have, that you develop with your aquarium. So when you look at that aquarium, you get a feeling from it. And it's hard to really quantify that. You can't really, but you can tell the things just look a little off. And that's what, you know, what we, I used to call that like someone who has a blue thumb. And I often found that, you know, people that were really good horticulturalists that had beautiful gardens tended to have really nice reef tanks too.

[00:08:04] Cause they had that eye for design. You know, I, I have a presentation I gave years ago at the Coral Osmentry Symposium in 2005 in the Netherlands about exhibit design. And this is something when I started my career at Waikiki Aquarium in 2000, in 1995, was really, you know, honed in on me by Dr. Ken Yates and Bruce Corls, Dr. Bruce Corlsson. And the people that I was working with about how you don't want to see anything.

[00:08:32] You just want to see the corals, the fish, and give you that illusion that you're looking at a live reef. You don't want to see pubs and cords. And that's what really, for me, separates the hobbyist from the professional aquarist. They're more interested in having a beautiful collection of corals. Awesome. The aesthetics sometimes leave a lot to be desired. And I see that in public aquariums too. There's not a lot of thought often given to the actual design. And that's just where the art comes in, in my mind.

[00:08:59] See, this is very interesting because, well, we're already getting very quickly into this. You mentioned Waikiki. So you worked there. But there is a lot of thought, as Charles said. There has to be a lot of thought because, and we're going to get into this, there has to be a lot going on, right? There's got to be lights. There's got to be water flow. There's got to be the coral set up in a certain way.

[00:09:27] But at the same time, you can't show any of that. You can't show any pumps, like you say, or piping or skimmers, or it has to look a certain way. So it is a balance between functionality and the way it looks or art, right? Exactly. And Joe, because, you know, it is, I mean, we're looking, we're basically dealing with two schools of thought here. I mean, you're working in a public aquarium. You're building public displays.

[00:09:57] So you have, people are coming in and paying, and sometimes paying a lot of money to come in to see your aquariums. If you're at home, nobody's, not too many people are going to come in to see your tank. And they're not looking to see whether they can see pumps or wires. They're looking to see what the corals and fish, what you have and what the health is and that kind of thing. On top of all that, we also have the aesthetic component. That's extremely important. And I have to say, you know, I've been in the industry now, what, 30 years, I think.

[00:10:27] And I've been to aquariums all over the world. And I still see aquarium, public aquarium displays that aesthetically leave a lot to be desired. And Charles, what would you say on a coral exhibit or habitat would be the basis of design with respect to the geometry, the profile, substrate, what do you try and design to achieve? And then you build from there.

[00:10:57] Well, I, the one rule that, I think that, the one thing that I often see that is not followed, which I always think is a mistake, and you see this a lot in architectural elements where people are architects and putting aquariums in homes or even exhibit designers for public aquariums, that the habitat really it's, you have to think of it as a living, breathing organism, mainly in terms of the gas exchange at the surface. And so what we tend to see are narrow tanks that are very tall.

[00:11:27] And that gives a very small surface area to volume ratio. So what you really want to do is maximize that surface to volume ratio. So if you're going to have a wide, a long tank and a tall tank, you want to have almost as equally a front back depth as it is in vertical height. So at least you're maximizing that surface to volume ratio because a lot of the products that are produced by corals are surface active products. So they tend to float on the surface.

[00:11:56] So you need to be able to break those up and you need a lot of water motion to do that. And there's a lot of gas exchange that takes place. So it's carbon, CO2 mainly and nitrogen and of course oxygen. And so having a large surface area really helps with that. So that's one design aspect that I often see not followed, which just makes me, you know, just almost tear my hair out because it's such a simple thing, right? And then also you're talking about animals that are,

[00:12:23] for the most part, are benthic in nature and they don't move. And so basically you have to have, you know, a substrate and a rockwork, what have you designed that allows for the spacing of these animals. And so they can get A, enough light and B, good water motion. And the other thing that people tend to forget, and when I see these tanks set up, they put way too much coral in and coral is going to grow. And so eventually it's going to grow into each other.

[00:12:53] It's going to, they're going to overshade other corals lower down. And as they grow, they're going to impede water flow. So you have to look at, to substrate the design of the rockwork. I also use a line of sight. I've looked out the front, I look at the rock. I can hide things like returns and stuff behind rock faces, as long as they're out of public view. I mean, you can see them if you look down at the top of the tank, but from public view, as long as you use, you know,

[00:13:21] the refraction index of the window and the water and other things, just like, you know, hiding the returns at the corners, things like that. So there's a lot that goes into that whole thought of the design of the habitat. So when you say the surface area, okay, you've got two things going on there. Number one, you have the action at the top, which is allowing oxygen into the water and it's allowing other constituents out of the water.

[00:13:50] So this gas exchange you talked about. Now, what do you, what do you mean about, so are you saying the coral are discharging something that skimmed off the top of the water? What exactly is that? Yes. So the corals have a mucus layer on them with varying thicknesses, and they're constantly shedding that off. And there's bacteria in there, there's proteins, there's probably amino acids, all kinds of things, particulates.

[00:14:19] And that stuff tends to be hydrophobic, so it tends to float to the surface. So that's why, you know, part of any analysis designed for a live coral tank, you need surface skimming so that you can remove that. And ideally, and I've already seen this at a few places, I was in Europe on vacation as well, Joe, this summer, and I visited several aquariums. And there was one that definitely did it right, where all the water that was coming over those overflows

[00:14:47] was going directly first to the foam fractionators. And these are the ones that are going to pull these compounds out before setting it to sand filters or what have you, or drum filters for polishing. And that's really important because these are all sources of nitrogen. And by removing them as best as you can before it gets to the rest of the LSS is really the ideal design. Yeah, Charles, you're right in my wheelhouse here. I thought about that when you were naming the compounds,

[00:15:16] mostly protein, nitrogen, and nature. Surface skimming, getting that to the LSS, having the factionator or the protein skimmer remove those compounds through aeration is a big deal. And I think that's important. Also for guest viewing, underwater viewing, clarity of the water, you know, the lack of turbidity and all of those things as well.

[00:15:44] What is your view on all of that? And as far as even disinfection, can ozone come into play here or you prefer to steer away from that? That's a good question. You know, I just wanted to go back to your comment about clarity. You know, there's an aquarium in Germany at the Karlsruhe, a natural history museum, which is just about an hour's drive southwest of Stuttgart. They have a large live coral tank.

[00:16:12] It's about, I believe it's 60 or 80,000 gallons. They have two black tip reef sharks in there. And they've had, they call it the shark tank, not the coral tank, but it's a beautiful live coral exhibit. And there is a haze in the water. They're not too concerned about it because actually it's kind of nice because then the sharks kind of just, just appear and then disappear. The fish, the same thing. And the way that it's lit, it makes those kind of animals disappear in the background. And, you know, a lot of those particulates are food for corals too.

[00:16:41] They're, they're coated with bacteria. There's a lot of literature about how the corals will take that in and use the nutrition for the bacteria that they ingest out those particulates. In terms of disinfection, it really depends on the size of the habitat. I know even home hobbyists that will use ozone, but, you know, they're not, because you probably know, Jeff, they're not using it properly or they, they have systems that are just not, you know, some of the units that are just not the right size for what they're doing.

[00:17:09] And they tend to over-ozonate because they don't really have a way to measure it properly. But we use it on our, at Steiner, we have a 212,000 gallon live coral tank and we definitely use ozone. I also use activated carbon. It's been on and off as we played around with the system over the years. But if I don't use the ozone, the tank will go yellow and green pretty quickly. And I have, you know, I have a presentation where I show like a time lapse where we had the ozone off

[00:17:36] and then we turned it on after, and after several months or even actually after a few weeks, you could see the change in color pretty dramatic. So it definitely plays a role in it, but I would, I think it's critical to point out that we're not using ozone for sterilization. We're not trying to kill anything. What we're trying to do is break down those coloring compounds into smaller pieces, which can be then food for corals, but they could also be more easily removed by activated carbon.

[00:18:05] Couldn't agree more, Charles. Ozone, UV, whatever the disinfection piece is to this, there is never sterilization in any of our systems. And when I hear someone use sterilization, it bothers me. Well, I want to be specific here and you be as specific as you want, Charles, but do you control that ozone via ORP?

[00:18:35] Do you say I want a certain ORP or do you say I want a certain color and I'm going to look at it and if it's not the color I want, I turn the ozone up a little bit. How does that work? Well, when I came originally, we had two very large generators and we had a giant manifold that sent ozone to all different habitats that we had. It was a result of value engineering and it was incredibly, it was, it was, it's a dirty word.

[00:19:05] And, uh, and, uh, the, uh, and so now you lost me, I lost my train of thought. I know that. I'll have to edit this part out. Value engineering screws, screws everybody up. No, but. So. You had this ozone manifold that was going to various different systems. Yeah. And so I, I saw, I looked at Andy Aikens and Mark Smith's presentation on AOD. So calculating the applied ozone dose. And I tried to do that with this system.

[00:19:32] And every time I would adjust the flow because it was a manifold, then it would adjust the flow and all the other fractionators and ozone in other systems. So we've actually, uh, we had a consultant come in and look at it and he asked us how many marine mammal pools we had to which we answered. Of course, no, we don't have any. Uh, so we had way, way too much ozone. So basically went back to the original design, which was dedicated individual ozone generators for every fractionator that we wanted to have it on as well as our freshwater contact chambers.

[00:20:02] So that allowed me to then go and, and get a better idea of AOD. But it, for me, it was more about the color. And I find that if you have the right color, then the ORP tends to follow, but it's not. We also do measure total residual oxidants. And that's really the main control, whether I'm putting in too much ozone or not. But our ORP target, like natural reefs tend to be between 320 and 380 millivolts.

[00:20:29] And that's kind of the sweet spot, but I don't really panic if it's 280. I look at the animals and I look at the water. Exactly. And I think, uh, Charles, you just pivoted back to the point we started the show with science, art. And I think about ORP and everything you just discussed. And everyone goes, well, 350 millivolts is the sweet spot. And that's within the range you just cited.

[00:20:58] 280 doesn't bother me either. And I, there's some people out there that go 400 is okay. But the point here is that you, there's a lot of sensitivity to our senses. What does it look like? How does it feel? And, and I think that's where the art kicks in. Do you agree with that? Yeah, absolutely. Absolutely. And, you know, that's really something that comes with experience because you've been down

[00:21:26] that road, you know, when, if you have a certain value set that things didn't look good. And so, you know, you don't want to go there again. And I would say too, that, uh, in terms of the applied ozone dose, there is no applied ozone dose recommendation for live corals. Like I couldn't find anything. They are all just talking about tanks. And I remember when we were talking about that, some of my biologists were saying, well, how do they know for corals that that's a good level? Like nobody knows because no one's really looked at that.

[00:21:56] So I, to be honest, I don't calculate AOD anymore at all. I haven't done so for years. I, I just found it to, I mean, our, our applied ozone dose was so low. It was like three decimal points below zero. I mean, it was low. So I never, I just didn't bother with it anymore. So when you sit down to, I mean, I know you have a well-established or a few well-established coral tanks, but theoretically, or maybe if you've consulted with other facilities, when

[00:22:26] you sit down and somebody says, we want to do a live coral exhibit. And they might not really know what that takes because I think that many people see a aquarium display with coral and they figure that's all living in there. But of course, most of the time it's fake coral made to look good because the real coral takes so much work.

[00:22:51] So my question is, when you sit down and you advise and someone says, I want to do a live coral exhibit, do they know what it takes? And what are the first things you say where you're going to need this and this? And do they get discouraged? Not necessarily. I mean, usually they go in having some idea what's involved. Like I don't think I've encountered anywhere where they don't really, because usually these are established places that have some staff, people on staff.

[00:23:22] But I will backtrack by saying, you know, that is the biggest determination or factor in whether you're going to be successful or not. I see all these designs for live coral tanks that these design firms come up with for their clients, but nobody looks at the human factor of this. Like who is going to maintain that? And what is their skill level? Because it's not necessarily an easy thing. And so some people might just back off just right from there.

[00:23:49] Or they, but I, you know, and I think as we've all noticed over the years, like I said, I've been in the industry 30 years. I have never seen so many job openings in the last five years posted as I have over those last five years. Before that, it was rare you would see it. So we're all struggling now to find good people and people with, and as you know, all of us started aging out that have this experience that it's been challenging.

[00:24:15] And I think one thing backtracking to the science as well, Dr. J is that a lot of the researchers now, these are much younger people and they have, some of them have grown up as keeping live coral tanks and so they have some skillsets already. And you know, that's where some of our best biologists have come from is from the aquarium hobby. You know, there are some, you know, there's some learning curves there about how public

[00:24:43] aquarium operates and what you can and can't do, what the expectations are. But that's where you get people that have a passion for it. And it's, it's very similar to jellyfish. People who keep jellyfish, you can't just throw anybody at it. They have to, first of all, want to do it. And secondly, they have to be passionate about it because it is challenging. And third moments where you can get very discouraged. And you know, I still get that, those feelings when things don't go quite right.

[00:25:09] But in terms of what people ask, I really want to know, like, I want to see the design. And it brings up one of the main points I wanted to make in this podcast is that when you're talking a live coral habitat and you're talking allison, it is a much more broader or broadly encompassing term than what people normally think of filters and pumps. It's now you're talking about light because lighting is critical for corals. It is a life support system component.

[00:25:39] There's no two ways around it. The second one is water chemistry. You have to know what the parameters are that you're aiming for. And you have to have an LSS design that can provide those parameters. And what I find is when people, you know, I look at designs, they're already so far down the road in the design and everything that they bring in somebody like me to help them out. And it's like, there's, it's like, you know, they will say, putting lipstick on a pig, right?

[00:26:08] You're trying to, okay, well, this, this shape and everything, it's going to be challenging. To get water motion in these areas. Like, how are you going to do it? Where are you going to hide stuff? There's not enough surface area for the corals or the walls are too steep. I mean, there's all these things. So my, I think what I would want most people to take away from this is that you've got to have people that understand lighting for corals. You've got to get people to understand water chemistry and they should be working with

[00:26:36] the design team before they even come up with a design. Because that's something that, you know, it happened here. I was brought in as a consultant and the whole tank was already designed, you know, and I could, I said, well, can we do this? Can we do that? There was some wiggle room. We could make some changes, but all of this stuff was already set in stone. Yeah. I'm chomping at the bit here, Charles on this, on your points are well taken. One thing I see is the client will come to me or you and they'll say, I want the largest

[00:27:04] coral, you know, aquarium in the world. Right. And they've got their eyes on this 300,000 gallon thing. Right. And oh, by the way, on day one, when we open up, I want it to just look spectacular. So how do you advise, how do you advise a client? And a good point you made is the lighting is a life support system. We all, we always think about water and water chemistry and all of that, but the lighting

[00:27:33] system is key to making this happen. So how do you maybe scale the client back and say, look guys, this is what we can do really well on day one versus you're not going to be able to do that when you open up. Yeah. It's, it takes a while for a system to, to really settle in and grow. I mean, our tank, we opened into the public in 2008 and Georgia Aquarium who had a tank

[00:28:02] that was also quite large, a little bit smaller than ours, but not by much. They opened in 2005. So we actually were comparing notes quite a bit. There's another very large tank that's been very successful at the Berger Zoo in the Netherlands. It's also about close to 200,000 gallons. It opened in 1991 and they specifically had a graphic on the wall saying, this is a living ecosystem. It will take time to develop and grow. Come back every year and watch it grow and develop.

[00:28:32] And I have photos from that tank. When I went, I first visited, it was in 1991 and it was just lots of rocks with cyanobacteria and a few corals here and there. And now I have a picture I took a couple of years ago and it looks, you cannot distinguish it from a live coral reef. It just takes a lot of time. In our case, you know, the direction that we received from our director at the time was just put a lot of fish in there. People won't notice that there's not a lot of coral. We had some coral in there. We were growing it out in the back in a special tanks.

[00:29:01] The problem was once you move them over, it's a complete shock to that system. The lighting was different. I could give a whole talk on all the things that we encountered, but bottom line is it takes a long time to grow. And what Georgia did was kind of interesting is that they installed artificial corals first. And they had a few pockets where they had live rock and they added some live corals.

[00:29:26] And their philosophy was as the things start to grow and spread, which is what they eventually started doing, but it took a while. And they started overgrowing some of that stuff or they would pull them out. And now when you see that tank, you can't tell that there's artificial coral. It's all overgrown with live coral. So let's get into some of these specifics. Basically, we're talking about lighting is important. Water chemistry is important.

[00:29:52] You talked about tank shape and the way you arrange corals and not to put too many in. How about structurally when you build that tank? Is there anything about the concrete or the rebar or the coatings, cathodic protection that needs to be considered? Absolutely. And it's even more critical for a coral tank than it is for a fish or a lasma brank exhibit.

[00:30:20] You really need to have somebody that has a good knowledge of how to build concrete for an aquarium and who can keep an eye as that stuff's being built. We've seen instances where the rebar is too close to the surface or the tie wires that they use is too close to the surface. So they begin to corrode and then it goes onto the rebar and now the rebar is corroding. So yeah, if you can do a carthonic system on that, that would be helpful for that.

[00:30:47] But it's mainly about the construction and what is the source of the concrete? Because this stuff will leach things out. So what's coming out of that concrete? And then the coatings are critical because they have to stand up over time. That same tank in Germany I was mentioning earlier, the curator actually searched out a company that was in former East Germany who did coatings for nuclear reactor chambers. And they put coatings on that tank that are rock solid.

[00:31:16] Yeah, I mean, the tank's been up for 20 years and you couldn't tell. It looks still new today. So that's on the extreme end. But I mean, those are the kinds of details you have to think about. You know, we started doing ICP testing of our water with charged plasma, OES as well as MS. And we started seeing huge spikes in molybdenum in our water.

[00:31:43] And we had a number of rust spots on the wall and you could see there was corroding rebar. And molybdenum is added to iron as a hardening agent. And so we had to have a company come in and dig out all this stuff, epoxy over it, put new concrete on top. And once they completed that, then the molybdenum started coming down very slowly. So that's something that, you know, as an example, what can happen?

[00:32:10] And molybdenum at certain levels is okay, but it was going up and up and up. Yeah, Charles, you mentioned ICP, inductively coupled plasma mass spectrometry or OES, optical emission spectroscopy. I think for our listeners out there that are into the coral world, these are very important analytical instruments that can help really look at the entirety of your water chemistry.

[00:32:39] Molybdenum, strontium comes to mind, other things that are micronutrients in some cases or contaminants in some cases. So you mentioned that and these are valuable techniques. Yeah, but let me ask this for you two chemistry geeks. When you're talking, Charles, about building the aquarium, we're talking about concrete leaching.

[00:33:05] We're talking about a rebar being too close to the surface or wire ties too close to the surface, which will affect and help corrode the surface. The rust comes through and will corrode the surface of the concrete. And we've got our coatings. Are you talking about it changes the water chemistry and that water chemistry affects the corals greatly? Is that what we're getting to here? Yeah, absolutely.

[00:33:33] That's why it's critical that you need a company that has experience in building concrete vessels that hold salt water. And you need somebody on site to monitor that pores to make sure that you've got that. I forget, you guys probably know better than I do, but I know there's a recommended depth that the rebar has to be, whether it's 18 inches or 12 inches. I forget what it is. But, and if you don't, that you don't know what's happening.

[00:34:02] And then the other thing is, what's the source of the concrete? Like, I know some companies are using recycled concrete. You know, what's, what is, where'd they come from? What was it used on before? Or that's why the coatings are important so that they basically prevent a lot of that stuff from coming out. Another example that there was an aquarium in Europe that they barged their water in. And they noticed that, well, they started getting very high zinc levels. And what was happening was that, and this also happened at a, at a U.S. aquarium in one of their holding tanks.

[00:34:30] They had zinc anodes in there for corrosion instead of magnesium. And so those, those little details like that, that you've got to have somebody like who, who understands that and can keep an eye on it as your system's being built. Very good point, Charles. Magnesium anodes versus zinc, or even worse yet, aluminum. So, back to alkalinity. Okay.

[00:34:56] So, in a closed system, you don't have natural seawater, but you're building in artificial seawater. And it's closed. How do you think about maintaining alkalinity? Do we have calcium reactors? Do we have, do we do additions of some sort of carbonate, bicarbonate sources to maintain healthy water for substrate and for coral development?

[00:35:27] Yeah, I, I grew up with the era of calcium reactors, you know, so that's what I knew. And that's what we had put onto this system originally. We had some calcium reactors that were added to our tank at Steinhardt from Europe. Unfortunately, they had some structural issues and failed quite frequently. So, we ended up building a couple of our own.

[00:35:47] And they are, they're challenging because it's always constant fiddling with the flow rate and the CO2 to maintain the pH where it's supposed to be. And then adjusting your flows and your CO2 to adjust the pH so you get the right amount of calcium and alkalinity. And as the media, you know, starts getting dissolved, then less of that media is reacting with CO2.

[00:36:13] And, you know, some, some larger public aquariums, especially in Europe, didn't like the fact that, you know, their pH was being depressed by all the CO2 that they were using. So, on the tours that I've done in Europe, I've never seen a calcium reactor. They're all adding the compounds. So, they're adding calcium chloride and sodium bicarbonate and also magnesium chloride.

[00:36:36] And so, they have large vats with where they pour these chemicals, the bags of chemical in and then they have dosing pumps. And then they monitor their levels and they fine-tune the dosing rate to maintain. And doing that, it gives you a much more stable alkalinity and calcium and magnesium levels. It's something that I'm looking at doing. It's, it's, again, when you go to North America, everybody's got calcium reactors. When you go to Europe, I, even the hobbyists don't use them anymore. It's all these solutions that they're adding.

[00:37:06] That, you have to do a cost-benefit analysis on that as well because when you're dealing with systems of 50 to 100,000 or more gallons, that's a lot of chemical. Yeah, this is good. What's a kalkwasser? A kalkwasser is a German term for calcium water. Kalk is calcium, Wasser is water. So, basically, it's calcium hydroxide that has been dissolved into water and then slowly added to the system. It helps to maintain alkalinity.

[00:37:35] The point at which you add it has a pH level of about 12 to 14. And that also, that precipitates out phosphate. However, now that we have ICP, we can measure all these other elements that are either trace elements or minor elements. And those will also get precipitated out. So, a lot of people don't use calcium hydroxide anymore for that reason. But there's some that still swear by it and will use it. Well, there's a lot of theories about the negative aspects of using it.

[00:38:05] And a lot of that is coming from the hobby. And there's no real quantifiable studies that have been done. As far as I know, maybe Jeff, you know. But I've never heard of anything. But there's a lot of anecdotal comments about what's good and why you shouldn't use it and why you shouldn't use it. Plus, it's very messy to use. And I think it's a powder. And it's, you know, you have to wear a respirator. And it's just really messy to use. Well, so we've talked about some things that we got to think about in design.

[00:38:35] Now, we've touched on a few things that we need to think about in terms of equipment, like a calcium reactor. Talk about quickly, because we have a lot of things to cover. Talk about water movement. Because we've got our LSS, which is recirculating our water in this live coral exhibit. But we need to move the water in a different way as well. So what do you do to make that happen?

[00:39:03] And why do we need to make that happen? Well, we'll start with the why. So corals have a mucus layer, as we talked about already, around the branches or if it's a boulder coral. They have this layer and it's called the diffusion layer. And water motion helps to prevent that diffusion layer from becoming too thick. So if you don't have enough water motion, that diffusion layer gets thicker.

[00:39:32] And the reason that's an issue is because the corals, again, as we said, they rely on water to bring and take away things. Waste as well as food. And so the wastes have to dissolve through this diffusion layer. When you have adequate water motion, that diffusion layer becomes compressed. And it makes it much easier for the coral to take up calcium and carbonate, nitrogen, phosphorus, and also to get rid of waste as well, like CO2 and things like that.

[00:40:02] Also to take up oxygen. There was a very interesting observation in 1997 or 1998. I think it was 1998. There was a worldwide coral bleaching event, Indian Ocean, Indo-Pacific. We were in Palau the year prior to that when I worked at Waikiki and the year after that. And a lot of the corals had bleached. But interestingly enough, a lot of the corals that were in the channels between the islands and Palau were not.

[00:40:29] And that's where this whole focus on water motion started in the scientific literature and how that would help with bleaching. So that's why the water motion is critical. Also, a lot of the corals have large polyps, so it allows them to sway back and forth so that the zoosanthella on all sides of those tentacles can get light as well. And so there's no real shading by the large polyps. And then... Sorry, Charles. You just pivoted to lighting. And I thought, these things go hand in hand.

[00:40:57] You've got the zoosanthella photosynthetic algaes, essentially, living that the corals utilize as part of their nutrition. It's a symbiotic relationship, right? Yes. The corals use the zoosanthella as an energy source in terms of the zoosanthella release amino acids and sugars and things like that that the coral can use.

[00:41:23] And also, we'll take up the CO2 that the zoosanthella produce. The coral will use that as well as a carbon source for calcification. So there's a whole symbiotic relationship between the two. And I want to get back to the water movement.

[00:41:40] So these systems need to be designed not only with extra pumps to provide the water movement across the face of the coral, the reef, but also there's got to be some sort of timing involved, right? Like timers or... Because it has to be sort of a back and forth movement sometimes, correct? In some cases, it does. And so what you want to avoid is a strictly laminar flow one direction all the time.

[00:42:09] Because what will happen is the tissue layer, that diffusion boundary layer on one side of the coral, it gets super compressed. And on the other side, it doesn't. And so you could actually have damage to the tissue as it gets pushed up against the skeleton. You know, and in the past, people would just say, well, let's just put bigger pumps on the LSS and that will give you more water flow or gives you more turnover. That's not the point here. The point here is that you want motion.

[00:42:35] And so you don't really need to put bigger pumps on your LSS because you don't want to increase the turnover rate. You basically want to increase the motion of water. So you can use closed loops. It's very common to do. And then now we have, of course, the large DC pumps like the Hydro Wizards from Pantoray and the Abyss flow cannons. And these are like a bit of godsend for people that are doing big coral tanks because now you can really place these pumps in locations that give good flow.

[00:43:04] But then there's an arc to that too and in the science as to where to put these things. And that goes hand in hand with the design of the rock work in the tank because just like people would have wave tanks and wave machines that they wanted to know what's the shape of what puts in the rock work and everything. They do their calculations. So that's very, very important. When I was consulting on the Steinhardt tank, our former curator, Dr. Ken Yates, was at Long Beach.

[00:43:32] So a former curator from Waikiki went to Long Beach and he had a large artificial coral tank that he said, I want lots of water motion. And at that time, PBS and Jay was still active in San Diego. And so they were doing the LSS for Steinhardt. And I said, I want that kind of water motion in our big coral tank. So we had a lot of flow in there. But because of the shape of the windows and the shape of the tank, there were still a lot of dead areas.

[00:43:57] And then there was an issue with our, this goes again to materials use in pumps and things like that. We had stainless steel check valves. We had three 40-horsepower pumps that are just for recirculation in that tank on the closed loop. And they had put in stainless steel check valves, which of course corroded away. And we had replaced them with PVC ones. But while we did that, of course, everything was down. So we got funding to buy on the Pantoray Hydro Wizards because that was the only solution at that time.

[00:44:27] And now we still have them. We have five of them in the tank along with other things. But yes, you want not just laminar flow, but you want more areas of chaotic flow. And even that can be created by the rockwork because the laminar flow hits that and it swirls off in different patterns. So you really want some back and forth. The deeper the tank, of course, the more challenging that becomes. And you can have some surge. So you have that back and forth swaying, which looks really nice.

[00:44:55] But you also have to recognize that that big, huge body of water that's doing that is putting a lot of stress on the rockwork and on the windows. And I've seen issues where leaking windows, as soon as we turned on these pumps, then all of a sudden we would start seeing water coming through the seams because the windows get buffeted back and forth. And in other systems that we have, a wave machine, the rockwork is just falling apart. It's crumbling.

[00:45:22] So, Charles, you mentioned this has been a great discussion about the kinetic motion of water and its importance within the exhibit itself. Can you speak to it? And you mentioned earlier, and I agree, that lighting is a life support system. So can you describe what sorts of lighting systems are required to support these coral exhibits? Yeah.

[00:45:47] I mean, as opposed to lighting that we use for an aquarium exhibit so we can see everything. The lighting for the coral needs to be different, needs to feed them, basically, right? Correct. You know, the zoosanthali, these symbiotic algae, what color are they? They're brown. They're a golden brown. Brown is the best color for absorbing blue light.

[00:46:11] And so, as we all know, as light passes through water, the wavelengths start being absorbed, starting with the red. The far reds are the reds, the orange, the yellows. So that's why the water looks blue, right? When you're looking at a wreath, everything looks blue because most of the other colors have been absorbed. The zoosanthali are adapted for that. So when you look at the lighting, you look at the spectrum of the light. That's important. A lot of people always focus on the intensity.

[00:46:37] The corals are pretty adaptable, so you don't need to always blast them with a lot of light. But we've got corals that are, you know, living at 50 par or even less, and they do just fine. And corals can adapt very slowly to changes in light intensity. But, you know, there's a sweet spot there, depending on the type of coral. But going back to the original question, like the spectrum is important.

[00:46:59] So you want to have a spectrum that's a little bit heavier in the blue area and a little bit less in the reds and oranges and yellows. And for years, that was always, there was really only one solution, and that was metal halide lighting. So now we have LED lighting. And LED lighting, you know, it's evolving at leaps and bounds. And the big problem I have with LED lighting is there's no historical data on them. We hear claims that they'll last 10, 20 years or longer.

[00:47:29] But no one's run them that long, so we don't really know what happens to them over time. And it's not just the LED, it's the electronics in the LED. That's the weak link is the electronics in these units. That's what's failing. And then eventually you get some diodes that will burn out as well or fail, whatever. So that's what everyone is now gravitating towards for the obvious reasons of savings and energy. And heat is a big one.

[00:47:56] Same with the DC pumps that are out now, smaller ones and bigger ones. We've seen tremendous drops in need for cooling because these pumps just run very cool. So it's the same with the lighting. So yeah, intensity, of course, is the other factor that's, as we touched on. But spectrum and intensity are important. And what I've seen is that a lot of these exhibit designers are the ones that are put in charge of developing the lighting.

[00:48:24] And they're hiring lighting companies that really don't have a lot of expertise with live coral systems. And I was recently visiting one, I was, well, last year. We did some readings on there. You could tell that it just wasn't the adequate spectrum for it. So there are companies out there, LED companies like Aquamedic and Maxpect and Kessel that have been working with people keeping alive corals. And that's what a lot of people are using now.

[00:48:51] But there are companies entering this field all the time and the technology keeps changing. It's just, it's, there's some questions I have about it. I mean, I did talk to one LED designer, the manufacturer and said, well, how long are these things going to last? And I did a, you know, envelope calculation about, okay, it costs me so much to replace my metal halides every year. I do it twice a year. What's my break-even point? Because these LED fixtures are expensive, right? You know, $6,000 or more.

[00:49:21] And what's my break-even point? Well, it was over 10 years. So is this fixture going to last 10 years for me to start breaking even on the cost? And what happens to the intensity of those LEDs? Do they drop over time? Again, we don't have a lot of data on that. So it's kind of a black box right now. That's what you're here for, Charles. You know what I mean? You're collecting all that data. So I'm going to move quickly here because we have to wrap this up. But we've talked about concrete. We've talked about tank shape.

[00:49:50] We've talked about water movement. We've talked about getting calcium in the water. We've talked about pH. We've talked about lighting. We talked briefly water chemistry. Quickly, can you just talk about makeup water, the water source, and how natural versus man-made, and how you might need to treat your makeup water prior to using it in a live coral exhibit?

[00:50:17] Well, for institutions that are making their own salt water, the source water is critical. What is the water chemistry of the water you're starting with? And what is the reliability? How variable are those parameters? There are some cities that have several sources of fresh water they can draw from. And in some cases, they're vastly different in terms of alkalinity. You know, it could be as high as one, one and a half molar equivalents to as low as 0.4.

[00:50:47] And that can vary over the course of the year as they change their source. And so that becomes a matter of you've got to be monitoring it every time you make your salt water. What are you starting at? Because that's going to determine how much bicarb you need to add and carbonate. The other thing that I've seen in a lot of cities, especially in Hawaii, because the water comes through volcanic rock, is that the silicate levels are sky high compared to normal seawater.

[00:51:12] And so now you're battling diatom growth on your sand, on your rocks, and it's a lot of work for your staff. Yeah. So really the best solution, and there are aquariums that do this, is they have large RO units, so that they're getting a very stable base water quality that they can then add their salts to. And real briefly, Charles, nitrate, right? I've been spending a life's career on nitrate.

[00:51:38] And when it comes to corals, aquarists and coral enthusiasts and people that deal like you, that are scientific about this, like a little bit of nitrate. So what's the ideal level? Well, that's a very open question, Jeff, because I, and I have a tank right now,

[00:52:04] that big coral tank, that nitrate level there runs between 35 and 40 parts per million. And our phosphate runs around 0.65 to 0.75. And I'm okay with that because everything is growing and doing fine. And the reason for that is that there's a balance between the nitrogen and the phosphorus. It's called the NP ratio. And it's a whole other topic. I got a whole presentation on it.

[00:52:30] But for me, that really has solved the big issues that we had with our tank. Because we have historical data going all the way back to 2008 when we opened it. And I can see how the nitrate and phosphate changed. And every single time when I had a low phosphorus level compared to a high nitrogen level, I had all kinds of issues with corals dying off, disease outbreaks, things like that. And it was because my ratio was much too high.

[00:52:58] And once we've dialed that in now, things are just taking off like gangbusters. And I've seen this happen. It's repeatable across different systems, not only in our building, but in other aquariums around the world that I've been able to get their data. So for me, ideally, you want it as low as possible, right? And the same with the phosphorus. But if it gets up to 10 or 15, as long as your phosphate is matching that and giving you a good ratio, which should be like in terms of molarity,

[00:53:28] I think it would be below 100, between 50 and 100. It's been my experience. Natural reefs, of course, are much, much lower. That's a whole other topic about how corals and zoosanthellies interact. How the coral actually forms the zoosanthellie to make sure they don't over-multiply, which is what happens when you have high nitrogen and phosphorus. The corals are going to get darker because they're going to have way more zoosanthellie. And that brings its own set of problems.

[00:53:53] But basically, if you're going to have a 10 ppm value of nitrate, not nitrogen, but nitrate, then your orthophosphate, PO4, should be around like 0.1. So those are some good numbers, numbers to take and sort of live by. I'm going to tee you up here, Charles, because we've had this discussion.

[00:54:19] And I think the takeaway is there's a lot of thought involved with the live coral exhibit. There's a lot of requirements to do it successfully. And you said that you've been brought in on projects when they were already designed and maybe already in construction, and you couldn't do, or you couldn't make the kind of changes you wanted. So I want to throw this to you, value engineering.

[00:54:44] We all go through it, but it's extremely troublesome when building or designing a coral exhibit, just because all the thought involved in it. That's what's your take on value engineering in relation to this? Well, I think that if someone's going to do that with a live coral habitat, they better think long and hard of what the consequences are going to be.

[00:55:11] Because, you know, we've had, every aquarium has this, right? You guys have probably seen it hundreds of times yourselves. And, you know, we have the same issue. They took things out of this Ellison's design that we now find is very problematic because we can't isolate a certain component now in order to do repairs to it without shutting everything down because there's no bypasses, for example. And when it comes to live corals, I mean, you cannot compromise on this stuff or you're

[00:55:38] going to be paying down the road and you're going to be paying a lot more than the amount of money that you're saving. Sure. No, it makes sense. And I just wanted to bring that up because Dr. Jeff and I, we talk a lot on this podcast about having the right people in the room at the right time, at the beginning of the concept of an exhibit. And this is just even more important with a live coral exhibit.

[00:56:05] So as our last question, Charles, what would be your advice or message that you'd give to to people out there, young people starting out in LSS and especially ones working with live coral exhibits? What's your piece of advice? Well, I think doing a live coral exhibit can be extremely humbling in that you quickly realize that you don't know anything, right?

[00:56:35] Right. No matter how much you think you know, there's a lot of stuff that you don't know. You know, it's the old line from our former secretary of defense about there's the known unknowns and then there's the unknown unknowns. So we don't know what we don't know. And that really applies to live coral tanks. So my advice would be, you know, you need to really explain, sorry, explore the literature, explore other people's experience and visit other people.

[00:57:04] It's the same advice I give to hobbyists. If you're going to follow somebody's advice, you better go see their tape because if you follow your advice, that's what you're going to end up with. So it's fairly important that you, that you recognize that you don't know everything and that you have a lot to learn no matter how experienced you think you are. And, and, you know, we talked about this previously offline about how, you know, I've been offered, offering people to help them with their systems. And they say, well, we already have people on staff.

[00:57:33] And then I go later and I see what they did. And it's like, okay, that's not bad, but it could be a, it could have been better or you could have avoided this issue and that issue. And, you know, really there's a lack of training and legacy training that's going in our industry, not just for live coral systems. But I think we're seeing it all across the board that a lot of the knowledge is disappearing with the people that have it that leave because we're not capturing a lot of that stuff.

[00:58:00] And so I know AZA is trying with their courses also as well, but in trying to provide training opportunities for certain things, but, you know, live corals, there's, there's a lot of good books out there and that even some of that are old are still good. But right now, everything, everybody gets everything off the internet. So that's a whole other ball of wax in terms of what's reliable, what isn't, but really it's experience. There's no replacement for experience and pick the brains of experienced people.

[00:58:29] And if you want to have a successful system, don't be afraid to, to offer or bring in a consultant to help you with it. Sure. I mean, there's people who have done it and we should rely on them. Think about corals, they grow so slowly. So sometimes you don't really know what success looks like for a long time. So last word, Dr. Jeff. I think we've covered a lot of territory today.

[00:58:56] And one thing that I think about, okay, there's left, there's left brain science and right brain creative art. And I think a lot of this comes into that, that where the two mix together. Um, that certainly is evident in the coral world. And Charles said it best. If, if you're going to take the advice of an expert in this industry, go look at their tank. And I think that was valuable.

[00:59:25] I just wanted to add something to something that you wrapped in your, in your wrapping statement there, that corals grow slowly. Nothing is further from the truth. These corals will grow extremely quickly. So you will see growth within a month. You will see signs of growth around the edges of these corals. And, you know, I have pieces that I've had for two years that went from the six inch frag to about 30 inches across. So the branching corals grow extremely quickly. The plating corals grow extremely quickly.

[00:59:54] Uh, we're now at the point in our system where we don't have a lot of space and we're going to have to start breaking things out to create space because things are starting to grow into each other and sting each other, which goes all the way back to what we were talking about earlier about design and placing your corals. It's a common mistake that people put corals too close together. They're not thinking two years down the road where that coral is going to be four times that size. So you have to constantly go in and be pruning it.

[01:00:20] And it goes back to also, you've got to have people that know what they're doing and are passionate about it because once that tank takes off and starts growing, it's like, you know, it's like having a rainforest, you know, exhibit where you, you have to be pruning stuff constantly. It's a big job. So the bigger you make these tanks, the more work it's going to take. And you have to, you have to allot for that when you're staffing. Well, thank you, Charles. I like that as the last word. That's even better. My pleasure.

[01:00:50] Thanks to guys. Thanks for the opportunity too. Yeah. Thank you to Charles Del Beek and thanks to MDM and Longhorn for sponsoring the show. And thank you all for listening to Inflow. Be sure to subscribe and leave us a review. And don't forget, you can always stay connected with us at inflowlsspodcast.com.