Episode 171: Heavy Metals & Living Soil: How to Pass Compliance Testing with Greg Larson

Welcome to the Cannabis Cultivation and Science Podcast. I'm your host, Tad Hussey of KISS Organics. This is the podcast where we discuss the cutting edge of growing from a science-based perspective and draw top experts from around the industry to share their Wisdom and knowledge. First off, I wanna apologize for the lack of podcasts in recent weeks. We had our big cannabis cultivation and science conference at the end of August in Bozeman, Montana at Collective Elevation, and it went really well. It was also a ton of work and preparation to organize. And then right when we got back, my daughter started first grade the next day. And then a week later, I was getting surgery for a total knee replacement and have been recovering ever since. It's taken a few weeks for the brain fog and pain to subside, but I'm feeling much better and plan on getting back into a regular schedule with podcast moving forward. Now, my guest this week is someone I've known for a number of years now and worked with on a few different projects where growers in tight regulatory states that want to use living soil or organics and have confidence in passing heavy metals are looking for solutions. Greg Larson is a commercial cannabis consultant specializing in organic living soil systems and heavy metal reduction, working across various commercial projects including South Dakota, South Dakota, and Minnesota, Greg has helped cultivators manage soil fertility, reduce heavy metal uptake, and pass compliance testing for market. Now onto the show. Hey, Greg, welcome to the show. Hi, Tad. Good to see you, man. It's been a little while since I last saw you at the conference at the end of August, but I'm excited we get to catch up and do this podcast. So why don't you tell listeners a little bit about yourself, And sort of your cultivation journey?

I'm just a dad. I've been into gardening for a really long time. Cannabis, tomatoes, yard gardening, kind of anything I can grow, I like to grow. I got into commercial cultivation, oh, probably 2020, I believe, when it went medicinal and recreational in South Dakota, then they overturned recreational. Opened an organic facility there. Kind of, you know, worked at a few other places after that. My first facility had a fire and it was kind of a tragic ending. Then just kind of bounced around and, and been learning about heavy metals here for a few years now.

So you're in South Dakota and you were cultivating in South Dakota where they have very tight heavy metal regulations similar to Maine recreational, California. I know there's a few other states that fall into that very, very tight window, especially for arsenic. And so you were committed to growing organically, and your facility initially had some issues. I remember because we were talking throughout this process, and you started doing a whole bunch of lab testing through Cannabis Chem Lab, who you introduced us to them. That's actually how we work with them now, was through you. So tell me a little bit about that process and what So what was your initial, you know, setup in your facility and where, what the results were, I guess?

We were initially running commercial grower's mix, and then we were kind of guessing at things. I think at that time we didn't know as much as we do now about heavy metals. I know that we did fine. ChemLab had switched machines to an ICP-MS. They were using a different standard before that. And a different testing method. We found a fail at the same time that we found— had a fire. So it put us in a really unique position to work together because we were like, okay, let's start from the ground up. I know we started testing kind of— I remember we tested like gloves, like, because we were looking for like, you know, why are these heavy metals happening? Where are they coming from? You know, what's the culprit in all this? Kind of just testing, you know, I kind of went into organics thinking, you know, this would be great. This, this isn't going to be hard as long as I follow what everyone kind of knew at that time, everything would work and then found out that that was not the case.

So you started testing pretty much everything that came in contact with the plant going from cultivation, you know, propagation, cultivation, all the way through harvest and cure. So you looked at Our soil, you looked at all of these fertilizer inputs, you looked at water, you tested, like you mentioned, trim gloves, I think you tested scissors, you've tested every single thing.

Yeah, I think some of the issue when we started was that we weren't testing through an individual lab, we were kind of testing wherever we could find someone to test. And we were getting these tests that were all over the place, we'd see a soil test at 2 parts per million, and the other will be 0.8 parts per million. And we're going, you know, none of this data aligns. So we kind of figured out that we had to narrow in and test with the same lab. And, you know, with chem lab, you know, it's easy to get upset when you fail, but eventually we kind of learned through, you know, talking with Jared and everybody, like, this is our standards, this is how we do it, we are a very accurate lab. So eventually we narrowed in on one lab, but I know in the beginning we were kind of sporadically testing everywhere, you know. We get a low test and we go, well, how could this be? Then we get a high test and we go, well, this is

So what were some of the outliers that you found in this process in terms of things that were higher in arsenic or lead or cadmium?

I know as we move through and working on a low heavy metal soil, we kind of test— I mean, I think there was a point where we tested pretty much everything. I think I was like, send me everything you got. And you sent me like a big box and everything went through the ICP-MS. And that's when we really kind of narrowed it down. Like we learned that alfalfa meal had way higher arsenic than we thought it would. And I know I ran that stuff pretty religiously before I, you know, found that out. 'Cause I'm a big fan of it. Do you remember what else tested high?

Some of the ocean-based inputs. Yes. Yes.

The fishbone meal was like, Obscenely high compared to bovine bone meal.

Yeah, all of the ocean-based inputs were definitely higher than the land-based inputs. That being said, one of the things I want to highlight for listeners is that application rate makes a big difference too. So just because something may be higher in heavy metals, you have to look at how much of it you're actually applying. And that, that plays a huge role in terms of how it impacts overall heavy metals. So Yeah, fishbone meal. You mentioned alfalfa. I would think that alfalfa would vary quite a bit. So, you just need to check your source or your batch because depending on the soil that it's grown in and how it's grown could dramatically impact it. But yeah, that was surprising.

It's tough for, I think, small facilities where ideally you should test everything that comes in. But, I think just from a monetary standpoint, Some people can't always afford that.

Yeah, we've published a lot of heavy metal tests on our website, you know, even some of the ones from you with the facility names blacked out. So we do try to provide that where we can. And we made the mistake, you and I talked about this, is initially we went with a lab that tests for heavy metals, but they were using something called an XRF gun, which just simply is not accurate enough for the testing that we need to do in cannabis. So the detection limits on that might be 5 ppm or 8 ppm. And so, anything below that would show as non-detectable. Well, if you were at 4 ppm and you added a whole bunch of that, you know, 4 ppm arsenic, you could dramatically impact the quality of your soil and potentially cause a fail. So, it is— that is really important. So, I love that we can get, you know, to parts per billion with Cannabis Chem Lab.

Yeah.

And, their pricing is, you know, not This is not an ad, but their pricing is, is very reasonable at $100 a test relative to what a lot of other laboratories charge for a similar service. So,

yeah, I, I, I like working with them and it's, it's affordable for sure.

So, I, I know when we worked with you, we then went back to the drawing table and reformulated a mix specifically for you guys. Trying to get as much fertility as we could in there without bringing in very many heavy metals. Because one of the things that you and I have talked about is how this is, this is something where we have to look at it as a cumulative effect. So all of these things that we're adding all are going to add a little bit of heavy metals. There's nothing is like perfectly clean. Yeah. But some things are definitely cleaner than others. So if we total all of the arsenic sources, if we're talking about arsenic, At some point in time, we're gonna reach a threshold that with those particular genetics in that particular environmental condition or facility can cause the plant to uptake enough to actually fail. Right?

Yeah.

So when you go to a facility now, how do you, how do you sort of approach that knowing that all of these things contribute something?

Typically I would want to test soil. I would prefer, you know, now we're at the point with soil where we know that we can mix clean soil. If I'm working with a facility, I can say, hey, these guys will give you a good deal on, you know, a commercial soil that will fill your facility. That's clean. That's proven. That's working. You know, nothing's ever 100% for sure, but you know, that's typically how it would start. And then, you know, irrigation, all the other variables. Kind of see, you know, what's, what's going into it.

Yeah. So, I know working with you on a formulation, we were able to lower our heavy metals even further than where we were originally. My thing is I'm not trying to create a completely sterile or soil that has very little fertility that's like perfectly clean. We need to hit a soil that has a lot of fertility still if we want to do, at least if we want to do living soils. Otherwise, you might as well just go out and buy some peat moss.

Well, that's another thing that I found is, you know, the lower the fertility, the higher your uptake. So you need to have the fertility there, whether, you know, you can, you can have the cleanest soil in the world, but if there's no fertility, it's going to uptake all, all the heavy metals out of there because there's nothing else for the plant available.

So talking about that, some of the, some of the highlights would be to make sure you Keep a higher pH, you know, closer to 7, 6.87, making sure that your phosphorus levels are at sufficiency. Do you want to touch on some of the fertility stuff in that regard?

Yeah, I found that bone meal can really push phosphorus. You know, now at this point, I like to do a week 2 test, and if I have to, you know, do any re-amendments, I can do them before flower set, and I can continually push fertility through a crop's production. That's, that's a big thing that I found is, is, you know, hitting that 2-week mark, getting that 2-week test into Logan, and making sure that everything's on point.

So you're talking about 2 weeks into flower, like when the plant's starting to go into stretch?

Yes. Like as you go into your flower sets, and you're really producing a lot of biomass, that's when I really want to watch phosphorus and just overall fertility. I don't want plants that are lagging real heavy going into that because That's when they're uptaking, you know, large amounts of nutrients, building flowers.

Yeah, that's a good point. Besides phosphorus, is there anything else that's a real red flag or something that you really watch for on these tests?

Iron. I always want to see iron insufficiency, zinc. Phosphorus, I think, is about the biggest one. That I found.

Because it shares a similar pathway to arsenic.

Yes, I think me and Brandon Hudson were looking through a book and then he found that. And then I kind of spoke with some other guys that were using phosphorus inputs and they sent me back numbers and they were using like organic-based, carbon-based nutrients that were really kicking their phosphorus super high. And I kept seeing big dives in their heavy metals. And, and as they started applying these products, they noticed that heavy metals continually dropped.

Yeah, there is research, especially in rice, that shows that sufficient— when, when phosphorus is deficient, that you'll see an uptake in arsenic. The— essentially, the plant will start to take up arsenic instead of phosphorus through that same pathway. So yeah, that's, that's definitely good advice. And I do want to highlight that you are passing, uh, consistently, and you're, you're passing consistently with very low heavy metal actually in the plant tissue itself. So like, your flower results are quite good.

Yeah.

Can you, can you touch on that now? Because I know this wasn't just something that happened overnight. You know, you found ways to continually lower that.

Yeah, I've noticed that, you know, running in a new soil, your first crop might be half a threshold. By the third or fourth crop, typically you taper down to really low, low numbers. And I think a lot of that's pulling out with biomass. I sent you those tests where we tested old leaves versus new leaves and kind of where arsenic is accumulating. And I think, you know, as you grow more biomass, you're continually taking this out of the system, not putting it back in. And yeah, I've noticed, you know, 2, 3 crops that we're really seeing just a nosedive in all heavy metal uptake.

Yeah, that's great. I like to think of it as, well, credit to Mike Wilson at Maincraft Cannabis because he sort of turned me on to this process, but thinking of it sort of like a mass flow equation. So essentially the amount of arsenic you want coming out in the plant biomass As long as that is greater than the amount of arsenic you're adding every cycle through fertility, and all of this is below threshold— and again, the threshold, South Dakota, very low. What is it for arsenic again, just to give listeners an idea?

0.2 parts per million or 200 parts per billion.

Yeah, so 0.2 ppm is, is a very, very tight threshold to hit. So as long as you're below that, But still pulling out some arsenic, then in theory, you should be able to continually go cycle after cycle. And have you found that some genetics are just impossible to run? Or have you had success across the board with all genetics?

I know that's very variable. I think that you might find a few outliers. But typically, running the program with clean soil, really clean inputs, I mean, you gotta remember, our inputs are super clean, like most of our inputs are under 0.2 parts per million. So We kind of mapped out all the super clean inputs and tailored the program off that. I've seen definitely higher accumulators, but I have not seen it fail since we implemented all this stuff, which is really lucky.

Yeah. So what are the— what are your favorite inputs then that you, you use continually every cycle?

Bone meal, soybean meal, feather meal, And then, you know, just basic other inputs, potassium sulfate, stuff that we can't escape, you know. The great thing about the bone meal is I've noticed that a lot of calcium comes in. So we've been kind of— I've been kind of void of having to throw in gypsum. But other than that, I mean, I chase trace minerals pretty heavy. You know, not— I'm not overapplying, but I always want to try and bring those up to sufficiency.

Yeah, I know that's where you deviate a little bit from Brandon and myself at KISS here. Our approach is we, we don't focus as much on heavy metals. I, or on, sorry, on micronutrients.

Yeah.

But I know you and Bryant Mason definitely have a much more aggressive approach with these. So yeah, I think that's, I think that's interesting.

Because you don't want to give a facility recommendations and have them mix up teaspoon or tablespoon and overapply and you can run into all sorts of issues.

Yeah, yeah, people just need to be careful.

A tough subject.

And then also, I think I would address sort of in terms of a priority, I would tackle pH and phosphorus first as, as the highest priorities, and then look at these sort of these micronutrients. And some of them are tough, like iron is a really tough one to get to sufficiency.

Yes, it's very stubborn.

As you know, because it immediately falls out of solution at the pH ranges that we're growing in. So what would you say then in terms of advice? So you really like bone meal, but I know there are people who are going to push back on that based on the conversations I've had with Jeremy over at Build a Soil and people saying, I want to avoid slaughterhouse inputs because I don't like that industry at all. What would you say to someone like that, or how would you address that in a state like yours that's really tightly regulated for heavy metals?

I, I mean, to be honest, I think you have to take a realistic approach of what you're up against and keeping your business going. You know, we, we don't have a whole lot of solutions in organics. It's not like we can create a new nutrient. I mean, you could look for an organically derived, you know, input and test it and verify it. And but I think, you know, I think some of this stuff is just hard to deal with, you know, you're gonna have to make a sacrifice somewhere, whether it's not growing organically in a commercial setting, or, you know, using animal-based inputs.

Yeah, I would also add that ocean-based inputs are not cleaner. So, and I don't know that they're necessarily—

Yeah, they're not practical. It's not going to work.

I don't know that they're more ethically derived in terms of our fishing industry. I don't know that it's necessarily any—

yeah,

it's a morally superior approach. I will say that if someone really didn't want to use those inputs, even though I would argue You know, I've said this like from a permaculture perspective that these inputs are the highest use case. Like the, our industrial meat industry is not going anywhere. Unfortunately, it is tragic. It is awful. But the using these to grow more plants versus putting it into a landfill or something like that is really the highest use case for these, these waste byproducts. And they are quite clean from the testing you've done, from the research I've seen. But if people didn't want to use them, I think another approach would be to use phosphoric acid. Yeah. As a way of getting available P. And then, you can get calcium from really clean gypsum if you test your source. We've been using a food-grade gypsum that's really, really clean. And then, things like fishbone meal for— or not fishbone meal, sorry, things like insect frass tends to be pretty low in heavy metals as well. I think a good general fertilizer.

Really, the thing I noticed with frass was higher cadmium every time we've tested it. Clean on arsenic, but the uptake in cadmium. I mean, there's a trade-off everywhere. You could use phosphoric acid. I don't know if that's necessarily considered organic if you wanted to, you know, really split hairs.

It's not.

It is if we add it with fish hydrolysate, then it becomes organic because it's a stabilizer. So.

Yeah, yeah. There's sort of cheat codes for all of these things. I guess I get less caught up in that these days and try to be more pragmatic.

You know, phosphoric acid is a great input if you're not completely handcuffed. Some people are, you know, more handcuffed. It's got to be organic and ready to die on a hill. Other people are practical and realistic about, you know, what they're up against. I mean, it's not easy. Commercial cannabis is not easy for anybody, anybody involved. It's a tough industry.

Yeah, so again, when you go into a facility, you're looking at all of these things. One of the first things you look at is, you said, all of these in, you know, inputs, what's touching the plant. What are some other fail points or concerns for a grow?

My biggest, irrigation. You know, how's your water system? What are you using? Is it RO? Is it, what's it running through? Is it brass hoses? All of that stuff is always definitely of concern.

So what are the concerns that people need to look for in that regard?

Typically, I'll just test off irrigation and verify arsenic. You know, if you find arsenic, you're going to have to backtrack and kind of figure out where it's coming in. You can test, you know, test off your tank and test off the end of your irrigation and find out if it's in that line. If it's out of the tank, then you know it's your RO system. So, you know, you might have to replace membranes or redo that system.

We have seen that with some growers where they have an RO system, but they're still getting relatively high PPMs out of it. And that just tells us that the RO system's not working properly. And so you do need to watch that. And then typically you want to buffer your RO system. If you have RO water hitting metal or other things, it could strip heavy metals from that, just that contact, because it is You know, essentially hungry water is what they call it. So,

yeah,

that's, that's a good point. And I've— we've also talked to people about making sure that when you do test water, you test it to a very precise level of test of detection similar to this, you know. So you have to use ICP machine in order to get to that parts per billion. Otherwise, it's really not a very useful test result at all.

No, I, I definitely utilize ChemLab for all that testing because I know that I have good accurate results and I can see even like, what is it, LOQ means that it's below, you know, they can test down to 3 parts per billion, but anything between 0 parts per billion and 3 parts per billion is like trace or detected, you know. So that means that there's something present there, there's just not enough to accurately measure it. And confirm what it is. So you need to watch for all that, especially in something like irrigation where you're, you know, constantly adding this to your soil in large amounts.

Yeah, this is— that's a really good point. So this is where application rate plays a huge role because we are using so much water in our grow. And I've had people say, well, you know, the water passed EPA standards for drinking water, and that's just not tight enough in some of these regulated states.

Yeah, it needs to be 100% clean.

Yeah,

there's, there's not much wiggle room when it comes to your irrigation. I mean, you got to figure it out, nail it down and get it clean. And, you know, don't be afraid to test it quarterly. Always verify. You don't know if it comes up, then by the time it creeps up in your soil, then you have a fail, then it's going to cost a lot more than, you know, a test every few months to verify That it's working correctly.

Yeah. One other thing I want to point out, because you mentioned soil, is the testing on soils, while important, is not going to be as accurate just because soil is not as homogeneous as we like to think of it. So that's where multiple tests and yeah, just keeping that in the back of your head, I think is really important.

Yeah, I think we've tested the stuff we've been mixing. I've tested it a number of times and I've never seen it shockingly high. You know, there's definitely variance, but it's always been at a really good level.

Yeah, that's a good, that's a really good point though. So, so just to summarize, you want to start with as clean of a soil as you can. You want to test all of your inputs, specifically avoiding those that are going to be high in heavy metals. You want to watch pH, watch phosphorus. You want to remove biomass. Can you touch on that a little bit?

Yeah, I want root masses out and all biomass removed. You know, all that biomass is, is, you know, cannabis is going to uptake arsenic. So the more biomass we pull out, followed up with clean inputs, the better that soil is going to become. You know, we're constantly removing large amounts of arsenic, you know, With biomass. I mean, we've tested old biomass versus, you know, flowers, and the old biomass holds considerably more arsenic than the flowers do. So all of that biomass is taking out, you know, failure amounts of arsenic we found where the flowers were still passing fine. So definitely biomass removal.

Yeah, I think of it like tuna and mercury. So like fish that live longer accumulate higher levels of heavy metals than fish that are short-lived. And it's the same within a plant, like older tissue is going to accumulate accumulate more heavy metals. So, if we can remove that from the system, that's going to effectively keep lowering that threshold versus chopping and dropping or leaving the root ball. Yeah. So, when you go to remove the root ball, how aggressive are you in that regard? Are you picking out every little root hair?

Pitchfork, dig it up. I want the whole mass out. Use my hands, break it up, Knock all the dirt off of the root ball and pull, you know, what I can get out. I'm not like sifting through the soil, but, you know, pitchfork will tilt your whole root mass up and then give it a shake.

So just removing the largest amount of—

Yes, within reason of time constraints. I mean, you know, you can't sit there all day. You want to kind of flip a room quickly and process a room quickly.

Yeah, that's also going to be your highest pathogen load. So if that plant had any Fusarium, hop latent viroid, any of those sorts of things, you're also going to be removing the majority of it by getting that root mass out of there. So it has multiple benefits in that regard.

Yeah. Another thing I found was, you know, appropriate drybacks. I don't have, you know, any research in cannabis, but I know we looked, I looked into Arsenic uptake in rice fields and anaerobic soils. So that's another thing is getting appropriate drybacks, not pushing irrigation as hard as you possibly can to risk anaerobic pockets in your soil.

So you like to keep it a little bit drier and make sure the soil dries out fully before?

Yes, I always like strong drybacks. You know, I can do a heavy irrigation as long as I'm drying back to an appropriate level. Watch intensiometers.

Do you see issues in terms of growth when you do have drybacks versus keeping the soil a little bit wetter?

Oh, you know, I've ran BluMat. BluMat seems to, you know, BluMat, I mean, I can't deny that it does better. BluMat's excellent. Just for me personally, from a dryback perspective, I prefer the tensiometers and dryback.

How dry are you letting the soil get?

Typically 25 kilopascals.

Oh, that's really dry.

30. Yeah.

Oh, wait.

No, that's, that's, that's 200.

Are you saying, yeah. Okay. Yeah. Yeah. Okay. That's pretty dry.

No, it's dry. Yes. But it seems to be working.

And you're still getting the yields that you would like out of the soil? Yeah. Okay, good, good. Well, what have we not touched on in terms of heavy metals and soil health in terms of the program that you like to run?

I'm not sure. I just go along with the flow, you know me.

All right. So one thing I want to touch on is you were working, you were consulting with a group that was originally growing in containers.

Yes.

And, and trying to do living soil in relatively small containers, and you definitely were having more challenges. Can you talk about that a little bit? Because you've— this facility is now converted to beds, right?

Yes, they still have another place in containers that's passing and doing okay. I know containers, you know, you have to be so aggressive on your feeding because you have such a small amount of feeding. And it's almost worth it to supplement with something. It could be a carbon-based organic fertilizer or something. It's terribly hard in containers.

Yeah, it's definitely more challenging, especially on scale too when you have hundreds of plants.

And their little place isn't necessarily on large scale. It's a very small family deal and they kind of moved into a building That's much more on scale now.

And so what did you see switching from these containers to beds, I guess?

Definitely less fertility issues, less kind of micromanaging small pots, lower nitrogen loads, you know, going in. Obviously in containers, you have to run your nitrogen so much higher in a soil report. Just to try and push through the crop. Heavy metals are always definitely lower in beds.

Oh, that's good.

That falls back to just kind of available fertility. We have such a large battery compared to, you know, 30-gallon pots, a small battery. I know when I started there, they were doing 15-gallon pots. I told them, you know, move to 30s. Like, trying to do this in 15s is too much, especially with the heavy metal. If you're at home, you know, you can get by on 15s in a grow tent. But in a commercial setting where you have very restrictive heavy metal numbers, at least go into 30s, give yourself some volume.

So even in— how are you re-amending the soil then? What's the flip look like between cycles when you are in pots like that?

Dumping all the pots out and putting in a whole lot of backbreaking work, then refilling pots.

So you have to take it, mix it all together, re-amend it, put it back into the pots versus what are you doing in a bed, for example?

In a bed, pull roots, drop, drop, you know, whatever your recommendations are and mix. It's all contained in one bed where you're not dumping out on a tarp and having to hand mix and go around and refill pots and move pots. Beds are much easier. 2 guys, 2 guys. What?

Yeah. So huge labor savings.

Oh yeah. 2 guys and 2 shovels can, can get a bed done quick versus pots. I mean, it's, it's, it makes you want to reconsider life decisions.

Yeah. So you're getting a soil test 3, 2, 2 weeks before the end of the cycle and always the same point in the cycle, every cycle. So you have a good data point and then By the time the cycle ends, you have the test results back, you have the amendments on hand, you have a prescription for what you want to go back into that bed knowing that it's going to be low in heavy metals. And then you're mixing that into the bed at the same time you're pulling roots and—

Yep. Typically I want to, want to pull 2 weeks before harvest, hit my amendments, then 2 weeks after the amendments go in. I want to redo my test to verify that everything that I put in hit the targets that I wanted it to.

Oh, that's that test 2 weeks into flower?

Yes. So I guess I can verify where all my amendments were and then I know, okay, I'm, I'm where I wanted to be. Everything's working correctly.

And how many tests are you doing for a room?

One.

So you get one homogenous, you make one homogenous sample out of the entire room. You're not testing every bed.

No, no, that would not be cost effective.

Yeah, we've done that and we've had growers do that and the test results are always close enough in most cases, unless you have a bed that's just a big outlier where the plants are just not doing well, or you have a bed that's like really, really thriving versus all the others, then we might do a test just to see what the difference is.

Yeah.

Yeah. But other than that, and that's also why we want to amend all the beds the same is so we can test with just one test. If you do a different prescription for every single bed, now you have to test all those beds. And that, you know, at a, you know, depending on if you're getting an analysis from us or just getting the test itself, even just the test itself is going to run you $60, $100 with the analysis. It adds up. So doing one test for the whole room, really affordable. One test for every bed, Really expensive.

Yeah, if you don't have any outliers or any reason, I, I've always learned that, you know, treat the room as a whole.

What about time downtime between when you harvest and when you plant back into that bed?

Um, 24 hours, within 24 hours.

So there is no downtime, so you're able to get cycle after cycle?

Yes, typically like go through harvest, get your harvest done, clean up the room, Get your amendments down, get all that done in a day. Typically, by that time, you're so tired, you can go to bed, wake up the next morning, come in and replant. You could replant the same day. But, you know, depending on how many people you have on staff, it can hurt your back. So 24 hours is my target for turnaround on anything.

That is also dependent on how much fertility you're adding. If you add too much nitrogen, for example, that can cause the soil to heat up, the bacteria and archaea will actually reproduce, which produces an exothermic reaction. It heats up the soil similar to the composting process. And, when that happens, that will make your plant roots very unhappy because not only can the bacteria access the nitrogen more efficiently than your plant can, so even if there's sufficient nitrogen in the soil, the plant will show a nitrogen deficiency, but that soil also heats up and plants' roots don't like hot soil. And so, making sure that your amendment prescription is sufficient but not too high to cause this to happen is really, really important.

Yeah.

So I just want to highlight for people who may not be quite as familiar with that. I know you know some of these things already. So any other advice then for growers who are thinking of setting up a facility or a new grow in a state like— I know a lot of people in Minnesota right now are coming online. I know you've done some consulting with some people over there. South Dakota, what sorts of things would you just say high-level recommendations for folks?

Definitely find someone you can work with and, and understands what they're doing. I think, you know, be, be very mindful of what you're doing. Work with your lab, get to know your lab, whichever lab you use, you know, they're a great resource. They, you know, they, they have the machine to test, so.

Test everything.

Yes. Do your research. I worked with ChemLab so much over the years that I've become pretty good friends with them. Do your research. Don't just jump in and expect it to work. You got to find the right people and the right company and the right team. And lean on other people. As anyone, as I'll tell anyone coming into cannabis, you don't know everything. There's, there's people that have been in this industry a long time that you need to show respect to and, and learn from and make friends with, because some of them make really great mentors.

Yeah, I think the biggest resource we have over at KISS here is just the network of amazing, like, growers and researchers that we can lean on when we have a problem. So, like, I know if I have a weird-looking plant, I know 2 pathologists that are amazing, you know, like Dr. Punja or Dr. Gauthier that I can send it off to, to figure out what the heck's going on. I know if I have an insect problem, I can reach out to Suzanne Wainwright-Evans. And so that network is crucial, making those connections, having people that are experts in things that you're not an expert in is really important.

And be

nice.

Make sure to be nice. Be nice. Just don't be mean. Be nice and it goes a lot smoother.

Yeah, I've definitely found for the most part, I've gotten a lot farther in this industry through collaboration than through competition. As you saw with the conference, you know, there's no gatekeeping happening. We just want to share good information and the people who are able to execute will execute on it, you know, so which, which I think is a difference. I have seen in Minnesota, and I just want to highlight this, I have seen people hire growers that didn't had never grown on scale to come into facility or ones that have grown on scale but have never grown with the methodology that the facility plans on executing with. And I just want to caution people to say that those are things that I've definitely seen be an issue before.

Yeah.

The other thing I've seen with this too is the expectation that that first cycle You're gonna knock it outta the park. And there's so much that goes into dialing in your environment, getting used to new equipment, all of those things. It's just good to plan ahead just in case that first run doesn't go quite as well as you, as you want it to.

Yeah.

So, well, awesome. Well, I appreciate you taking the time today to chat. Is there anything else you wanted to share, uh, before we sign off?

No, I got nothing. Good to see you.

Good to see you, Greg. I appreciate the hard work you're putting in over there on the East Coast to help people with, with passing and some of these heavy metal challenges that we're seeing in these really tight states. And yeah, I hope we'll stay in touch.

Thanks, man.

That was Greg Larson, and you were listening to the Cannabis Cultivation and Science Podcast. If you like the podcast, please leave us a rating and review and give us a follow on Instagram and YouTube. And don't forget, at KISS Organics, we have a wide array of products we offer on our website, ranging from soils, amendments, and beneficial insects to soil test analysis and commercial consulting. We carefully research all the products we offer and manufacture to make sure they are science-based and meet our highest standards of quality. Thanks for listening.