Seth Baumgartner and Jason Van Leuven open the mics for your crop steering and cultivation questions.
Kaisha [00:00:00]:
Foreign what's up, Gromies? Welcome to AROYA Office Hours, your source for free cannabis cultivation education. I am your moderator, Kaisha. This is episode 127, shout out to our live viewers on YouTube and Instagram and to everyone tapping in on Spotify, Apple Music, YouTube, or wherever you listen to your podcast. Thank you so much for your support. If you like the pod, drop us a review. We absolutely appreciate your feedback. Jason and Cian are in the house. Guys, how you doing?
Cian [00:00:31]:
Doing great, Kaisha.
Kaisha [00:00:32]:
Fantastic.
Jason [00:00:34]:
We're doing good.
Kaisha [00:00:35]:
Wonderful. You ready for our first question?
Jason [00:00:39]:
Sure, let's hit it.
Kaisha [00:00:40]:
All right. Let's get into it. All right, so Billy dropped this one. It's lengthy. I'm gonna read through it and we'll talk about it. So you're right. How's it going dudes? Hope you're having a wonderful Thursday. We have an issue we've been struggling with for a bit and have a few paths we're thinking about taking.
Kaisha [00:00:53]:
Would love some insight. Around week three to five we see our runoff PH fall to the low fives or into the fours after the plants have been otherwise raging for multiple weeks. We run 1 gallon coco, 3.7 EC, 6.0 pH, front row ag pretty even canopy par around 1100 PPFD, 1300 ppm CO2 and minimal swings outside of our 1.1 bpd target at 81 degrees leaf temp. We run a pretty tight irrigation window with 0.5 gallons per hour wips and 2 minute shot space. 10 minutes apart until we hit field capacity plus 200 to 300 ML runoff, then begin drybacks for 22 plus hours. We are debating between running a lower EC and pushing more runoff, running a higher feed and pushing more runoff, keeping the feed strength the same but adding more shots to increase runoff or hand feed reset of our blocks once a week. The vig, the big volume all at once from a hand feed has been effective at resetting ph, but it comes with extra labor that we would love our irrigation to handle instead. We don't want the blocks to channel when sending a lot of volume through the lines too quickly.
Kaisha [00:01:57]:
So we were wanting to know if you have any pointers on steps we might take to achieve better runoff ph going into our bulking. You guys are the best and we appreciate everything you do.
Jason [00:02:06]:
All right, awesome question. I mean I, I love how he's given us so much information to get a great answer to to them in this question. So you know, for. And then just nail it. Channeling. Usually we only see it if we get things too low, and that's especially in Rockwool with coco, I can push down to typically, you know, 15 to 20% and not necessarily see too much channeling, especially with like a 0.5. If I'm at a 1 or 2 gallon dripper sometimes I'll see that a little higher water contents. But yeah, don't get too worried about that.
Jason [00:02:43]:
I do think that we are hopefully can provide some information that you won't have to hand water there. So at, you know, 3.70 C, 6 pH, front row AG, everything is looking pretty good in there. And if we're looking at weeks three to five, I guess my question would be is where are we ending those generative strategies? Right. So if we're adding P2s at week, say 4 and that's what's ending up correcting the ph that you're seeing, then I, I would probably just feed a little bit heavier earlier on and you know, you go up to four and see if, if that fixes it. Obviously when we talk about PH runoff, we're always looking at what is our nutrient composition balance. And I pull up that, that PowerPoint all the time that has, hey, here's our cations, here's our anions, right? So if we're feeding it at six, that means that, okay, this is the, you know, where we're at with that balance and some ph correctors and that fertigation system. When those plants are uptaking some of those nutrients, it's not always exactly as it's supplied. So sometimes they'll be pulling, let's see, in this case they're probably pulling a little bit more anions.
Jason [00:04:00]:
I'd have to look it up. I always get, get the ph is a little bit goofed up with the it's negative log, right? So basically it's running out of negatively charged ions in there. That's why it's dropping. And so when we up that feed a little bit, sometimes we can just balance out that nutrition that's being supplied to the plants and you won't necessarily have to push a higher amount of runoff. Basically what you said is both of those are good options. So you know what I wouldn't do is lower my feed as far as the options that you've provided here. So I guess there's two parts to my answers here. One would be if when you're switching to vegetative it corrects that ph, then I, I may not get too concerned, but you could just up your, up your EC during say weeks Two, three, if you've got really good EC levels, say in the plant at like four to seven, coming out of edge, then.
Jason [00:04:58]:
Then you could actually do up that, that EC first week even. But, you know, if not, then, yeah, weeks two and three, you could up that ec, see if that corrects things. You know, the problem with adding, adding P2s for runoff is now we are actually kind of starting a slightly vegetative type of irrigation. And some plants don't mind that. You know, when we talk about vegetative versus generative, it's always that, that one or the other. And this is where the, the spectrum comes in where. All right, for some plant types, we can actually run a little bit more balanced and, and we're seeing a really good result. Obviously.
Jason [00:05:38]:
Typically when we're pushing for a generative, it's to one, establish the correct plant physiology as early as possible in the plant life cycle. And a lot of times for, you know, things like, you know, LCGs, we actually go a little bit more generative pretty much the whole life cycle. So for, for these plant types, the first steps I would take, yeah, you just up the ecs and, you know, weeks two and three, if that's not an option, then, okay, let's just push a little bit more runoff. So it comes down to logistics as well. Like, all right, ideally, sure. Let's see if a little bit higher EC fixes the runoff pH during those weeks. You know, if it sounds like it's correcting itself by the time that you're back in vegetative may not be a huge concern anyways. But you're, you're kind of on that.
Jason [00:06:22]:
Like, all right, we're, we're an A grower, so let's get to an A plus grower kind of range. And that would be an option if that's not super easy to do. You know, you've got shared batch tanks, your direct inject for multiple rooms, that type of thing, then, yeah, just push a little bit more runoff. See if it, it keeps it above, you know, above like 5, 3, 5, 4, 5, 5. You know, if you can keep that pH runoff at 5, 5, then we know our, our, our imbalance is probably not affecting plant growth at all. You know, if we're lower than 5, yeah, it might be substantially affecting plant growth. So those would be the first two steps that I, I would take in this situation. But, but yeah, you know, if it's correcting itself by the time you're back in vegetative, you might even just.
Jason [00:07:11]:
You might even just Ramp into vegetative. You know, a lot of times we talk about it, it's like this is one or the other. If you have good ability to manipulate irrigations based on the, you know, the day, or you want to put a little extra effort in there week into week three, you know, week four, then, all right, let's just start adding P2s in there. And that might correct your PH a little bit sooner. And it comes down to how your plants respond. Are you seeing negative effects, deficiencies in our elemental composition, in the nutrients on the plants? If not, then, you know, maybe it's correcting itself quickly enough with your vegetative irrigations that you don't have to make huge changes. Super fun question because it's like you're doing everything right.
Cian [00:08:06]:
The one thing I was kind of thinking of is, you know, if you're not trying to potentially push too much more runoff, maybe just looking at increasing the time you're allowing in between your P1 shots to be able to extend or, sorry, decrease your total dryback window just a little bit, sometimes that can help kind of reduce the intensity assault buildup in such a way that you're not fighting yourself when you are trying to raise that, that input EC a little bit. But like Jason said, sounds like you're doing the majority of the equation just the way you should be. And pushing too much more runoff may well, you know, not be an option that is a, cost effective in labor like you were talking about, and B, may not result really in pushing your plants to do the best they possibly could. Because like Jason said, some strains out there really do better when driven harder generatively earlier on and ramping that, as Jason said, right up into your vegetative stage.
Kaisha [00:09:20]:
You guys have given Billy a lot to think about. Thank you so much for that. Jason, something you want to add?
Jason [00:09:26]:
No, I was just adjusting.
Kaisha [00:09:28]:
Okay. But then also just want to mention we dropped one of our education guides in the chat. Some five facts everybody should know about ph. So, you know, putting it all together. Billy, keep us posted on how it's going. And thank you so much for submitting your awesome question. All right, I'm going to keep it moving here. We got this right in from Northbrook Farms who wrote.
Kaisha [00:09:51]:
So I'm having an interesting problem with saturation. We are in 1.5 gallon coco pots and are hitting a VWC of 77 to 80%. However, we ran the same brand of coco in 1 gallon pots before and our Max BWC was only 65 to 70%. I'm thinking the sensor could be too low since there is no slot for 1.5 gallon pots on the sensor placement tool. Another strange thing is that the BWD VWC increased throughout flower, not decrease like they typically do. What do you guys think? Thank you and have a great day.
Jason [00:10:25]:
Yeah, you could be absolutely right. You know, it's one of those things when, when I recommend to people anytime that they're using a new media or they have any concerns about those exact numbers with BWC being read from the sensor that is do do some tests, you know, get yourself a kitchen scale and saturate the media. So, and anytime I'm doing any changes, especially in coco, I like to. So I will saturate my substrate. You know, whether it's 1 gallon, gallon and a half, 2 gallon, 3 gallon, I'll, you know, completely compressed block, I'll saturate it typically with something like, you know, 6PH0EC. And then I want to see what happens in the runoff of that. This is going to do us a couple things right. You know, having that runoff is just validating that our COCO is well buffered.
Jason [00:11:23]:
It kind of gives us an idea of what the native EC in that coco batch is. But in your case, after it's been saturated, let's get that one of those sensors in there. If you have a solis, you can check it with your solis. If you have an arroyo sensor, stick it in there for 10, 30 minutes and you'll get a few readings from it and that'll give you the reading water content. And you can compare that with what your actual water weight is in there. So that kitchen scale, I was talking about weight compressed block before you saturate it, that'll give you your dry weight. And then we will saturate it, make sure that we've got a good saturation. You know, we did get a little bit of runoff, but it's no longer running off.
Jason [00:12:06]:
Then weigh it again at that, I like to call it field capacity because it's a little different than saturation. But weigh it at that field capacity point and that'll be your dry matter plus water weight. Right. So let's subtract the dry weight from that and we'll know, hey, that's the water that we added to this. If you do a little division, that'll give you your percent water content by volume. Right. So we know. All right, let's say we got, you know, it's 1200 grams of water in there.
Jason [00:12:36]:
So that's 1200 milliliters. Also nice. The metric System does that with water. If we divide our volume by that, you know, volume of the substrate by that, then that gives us our volumetric water content. And that there, you know, there's really no calibration or adjustment as long as our kitchen scale is correct, an absolute value. And what we can do is we can adjust our sensor height just slightly to completely match that substrate. Obviously with the template tool, you know, we, we did our best. We ran multiple sizes of substrates that were available at the time and said, okay, this is a pretty good approximation of those water contents for that substrate size and then broke it down.
Jason [00:13:16]:
So it's mostly as easy as possible for the users. If you have a substrate that's not necessarily standard, obviously there's more and more sizes and types of cocos coming out now than when we built those templates. Then you can just build a template for yourself. Right, So I think we're at what, like one and a quarter for one to two gallon, or maybe it's one gallon at one and a quarter, two to three gallons at like two inches. Yeah, just measure up from the bottom. You can use a piece of cardboard. If you want to get fancy, use a piece of wood, plastic, whatever. Mark your height.
Jason [00:13:49]:
I used to just use a ruler for all my installations back in the day. And sure, we might be at 1.6 is giving us the most accurate reading for that substrate. Specifically.
Cian [00:14:04]:
I was going to say the same thing. My experience with mine. Whenever I see numbers that are trending on that higher end of things, the first question I ask is, have I poked my sensor a little too low? Or sometimes have I put my sensor in and a position where its tines are poking a little bit too low every once in a while. Not ideal, but I have found myself, you know, with a careless installation of my own making where I pointed the tines down a little ways, where I'm like, oh, well that, that figures. I'm seeing a little bit higher numbers than I was expecting with this one. And, you know, just double checking yourself with those things. Like Jason mentioned, using a ruler is a great way to be able to find a custom placement. Um, I've experimented with a bunch of different mediums over the years and had to find placements that, you know, were not necessarily on the template at the time.
Cian [00:15:00]:
And experimenting with both, you know, doing the method Jason described, weighing things out to try and be able to ascertain pretty accurate VWC measurements and understand your substrate that way is a wonderful way to do it. I've also gone a little bit Lower tech and just gone on the fly with a solace and poked, you know, a number of pots around the room at differing heights with that ruler and figured out what seemed to approximate the most usable water content over the time, too. I would say Jason's method is by far more accurate. However, in a pinch, you can bring the, the sensors into a position that gives you a lot more clarity by, you know, making sure that you're getting a reading that's similar on each sensor each time that you're actually getting it. Rather than, you know, maybe this guy put the template a little bit, you know, wonky when he placed it, or maybe wasn't paying attention like me, and poked it down through the substrate. Little things like that, along with measuring a consistent height that works well for your substrate, can definitely do quite a bit with correcting high numbers like that.
Jason [00:16:21]:
And there's a second part to this question that I want to make sure we try to address at least, I don't know if that we're going to give you the right answer for it, but you saw your field capacity numbers were increasing over the, the cycle, right? So let's say, all right, day five, we saw a field capacity at 72%. At day 30, we saw field capacity at 76%. Lots of kind of physics and stuff going on here. There are some coco manufacturers that actually will variate the different pith of the coco from the bottom to the top. You know, maybe we're actually washing some of the, the smaller chipped, the smaller pith coco down towards the bottom. It's gonna have a little bit higher water holding capacity simply because, you know, they're smaller particles. There's more surface area to hang on to the water, you know, and on the other side of that, obviously, when we're in smaller medias, sometimes we see those numbers go down. We've got roots that are one building matter in the substrate.
Jason [00:17:29]:
They're compacting some of that substrate. And then on the flip side, you know, they're also building capillary space, which the sensor is reading the amount of water in your roots as well. So when we think about, all right, coco to start with, it's mostly just airspace and coco and water fertigation. Water. Right. And then when our roots are growing in there, well, now we've got some amount of root mass, but we've also compacted that coco and those capillaries are building and filling with water. The sensor doesn't know if that water is in the coco or if it's in those actual Root capillaries themselves.
Kaisha [00:18:11]:
Fantastic, you guys, thank you for that. North Fork Farms, thank you so much for your question. Good luck. All right, well, we've mentioned the solus a couple times. We actually got a question about from a Solus user.f90 wrote in. Hi, guys, Greetings from Germany. Just got my first solus sensor and my poor water EC always go down. Goes down with my dry back, shouldn't it be rising? I'm in a 5.4 liter pot using Canna Coco Professional plus substrate.
Kaisha [00:18:38]:
Day 13 of flower running 1100 PPFD and 1.2 KPAs. Feeding Canna Coco and AB steering gen trying to stack some EC feeding pH at 5.8 EC 2.2 dryback is 20% VWC. With my P1 irrigation, my pore water EC goes up to 2.3 and at the end of P3, my poor water EC is 1.7. Runoff 20% of irrigation volume pH 5.9 EC 2.2. Plants look fine. What do you guys think about that?
Jason [00:19:11]:
I think you're underfeeding. Really the only time that I see that EC goes down when our water content goes down is just that, hey, the plants are actually eating nutrients faster than they're eating the amount of water in the substrate. Super easy solution. Just give your plants more food. And this is actually, I've been working with a number of European growers and it's kind of like where, you know, we were at stateside here maybe five, ten years ago was people were really scared of burning their plants, feeding it nutrition levels that actually tomato growers pretty much typically grow at.
Cian [00:19:48]:
As far as conventional wisdom told us. No, don't do that. Don't, don't jack up your feeds. It's going to burn all your root systems away.
Jason [00:19:55]:
Yeah, yeah. You know, and the cool parts, we've got enough science here to kind of explain that, you know, cannabis doesn't necessarily burn nutrient burn until we're way up there in EC levels, you know, 10 plus like well over 10. You know what those signs are typically nutrient imbalances or ph corrections that need to be made. So, you know, if you're seeing 1.7 on EC anywhere, feed EC red zone EC and you've got, you know, a solace that's tracking that. That's. That seems like a pretty easy answer to me, is let's make sure that we're feeding it 3 to 4 EC at the minimum, as long as our environments are appropriate.
Cian [00:20:42]:
Couldn't agree more. Bump that feed up a little bit. A lot of times if I see numbers like that especially early on in my growth cycles. I'm like, oh, these ones are eating very, very quickly. Let's, let's give you more food and make sure that you have everything you need to keep growing big and strong.
Kaisha [00:21:01]:
All right, you guys, thanks for your insights on that. I'm just going to share this comment from Bangxiety. See, I don't know about that. My EC will drop overnight too, but I think that's the sensor not reading properly with low water and pot because as soon as I water some, it goes back up to what I figured it was at.
Jason [00:21:19]:
Not sure, maybe not enough info in there. Usually specifically with the Taurus 12s, when we're in low water contents, our ECS will actually be approximated too high. And that's why kind of this first answer was, was super easy because, you know, of the tens of thousands of charts that I've looked at and with the Tarot 12, you know, on those solaces, for example, like that EC is going to go up even when we're aired because of low water contents. You know, when we're looking at water contents less than, you know, probably like 25% that Teros 12 has a little bit harder time than the Teros one getting a really accurate EC level. That being said, you know, it's kind of something that, you know, we'd expect is it's going higher. If you're using Teros 12 and your EC is still going down when your water content's going down. Yeah, you got to get more food.
Kaisha [00:22:13]:
All right, there it is. Thank you guys for that. Thank you for the question from Germany. Good luck. All right, we're going to keep going here. We've gotten a lot of live questions, questions on YouTube. Thanks Chromies for dropping them. Dustin dropped this one.
Kaisha [00:22:25]:
All right, for someone who is just learning what is the order of importance PPFD, slab EC runoff, EC getting proper dryback, CO2 VPD. Does the importance change with yield versus quality? Good Mid ground. Side note, largest issue I have is getting temps in check when running 1050 PPFD, but can keep them in check at 900 PPFD. All right, so what do you guys think? How would we address this order of importance?
Jason [00:22:54]:
Yeah, so there's a pretty easy answer for, for me to start this with. Obviously when we get down the chain of importance it gets a little bit more, more tricky. Right. But when we're looking at the photosynthetic equation, we have, you know, CO2 plus water catalyzed by light Is it's giving those sucrose molecules that the plant's growing from. So CO2 levels and light. If we don't have enough light, we cannot catalyze the appropriate chemical reactions in order for the plant to build up to its potential. Right. So, you know, making sure that we have those 8 to 1400 PPFD levels, depending on the strain.
Jason [00:23:44]:
You know, if you don't know anything about the strain, then yeah, go 9 to 1100 peak in flower and then obviously CO2 levels. Yeah. For our mixed light growers, outdoor growers, yet you don't have the opportunity to. To increase that as easily for indoor growers. My general rules, we always want PPFD plus 200 equals our ppm. All right? So in this case, let's say I'm a thousand PPFD. I want to be probably at 1200 ppm floating for my CO2 levels in there. So those are pretty much the most important first ones.
Jason [00:24:22]:
You know, the caveat there is always, well, everything kind of else has to be in check to make the best of those. Right. You know, if those are. Those are cattle or. Yeah, it's. They're catalyzing and founding the best growth for the plant. We also want environmental levels to be correct. So anytime that I'm working with a client and I haven't looked at their graphs or their new client, I don't even look at Ritz own stuff until I look at their environmentals.
Jason [00:24:52]:
One, for the most part, outside of facility constraints, environmentals are the easiest to fix. Making sure that, hey, I always look at temperature and vpd. So when I look at a graph, I typically have VPD and temperature on top, water content and east, see on bottom. And I'll start with the top graph. All right. Our temperatures, where we want our temperatures to be, are the temperatures we want them to be appropriate for plant growth. Those are the kind of the two questions. And then we look at vpd.
Jason [00:25:25]:
Is VPD helping this plant grow to the best of its potential at that phase in its life cycle? Right. So, you know, early on, say late veg, we're looking at VPs. We want them 0.6 to 0.9 early flower. Let's 9 to 11 mid flower. You know, we're shooting for 1 to 1.2 late flower. We may push up to 14 if we're trying to combat botrytis and molds and mildews. Typically that 1.2 range is pretty good if we're not trying to combat that. So that's where I Start with, if those are all in check, then we'll work through our EC levels, our water content levels.
Jason [00:26:09]:
Right. EC levels. We're looking a lot of times at the trending of those charts. Kind of roll back to that last question we had. There is. All right, what is the EC doing? Is it showing that the plant has enough nutrition? Is it critically low? Not very often do I actually run into it being critically high. Typically, you know, by the time that I'm out of veg, I want my root zone EC to be in that 4 to 7 range and kind of answering some of more of those questions like, all right, well, runoff EC or red zone ec once you've got a grasp on your red zone ec. I don't.
Jason [00:26:51]:
I wouldn't even waste my time looking at runoff EC personally. Those sensors in that red zone are telling you what the plant's feeling right? When we're doing things like our first question, pushing a little bit more on, off, or, um, upping ecs to fix runoff ph. Yes, runoff ph. Very important because it's one of the only things, other than leaf tissue analysis that can tell you about nutritional balance. That being said, our runoff EC used to be important until we had red zone sensors. Now that we have red zone sensors, we don't have to use runoff EC to infer what that level is in the plant's red zone.
Cian [00:27:30]:
That is a just really, really well stated answer, Jason. You went through all of the major points and like, in the. The exact way that my mind came to him too, is just, you know, being able to look at how much light, how much CO2, do you have water and nutrients that are appropriate. Those are your basics, right? Like, you know, say you're doing all this in a tent in your basement, and you only have limited resources. Focus there first. But also, do you have appropriate heat and airflow? Can you get CO2 in there to be able to match your lighting? And all these little questions that start kind of predicting whether or not you're going to be able to have the type of success that you want with it as you scale. Kind of like Jason said, all of those factors need to be working together in concert in order to be able to really achieve the success that you want. And that even, I would say, becomes more important when you start looking at the upper echelons of, you know, what you're trying to get with yield and quality.
Cian [00:28:37]:
All of those factors have to be working together in the right ways to be able to maximize the success you can get out of individual cultivars.
Jason [00:28:45]:
Yeah, I know I'm doing a good job over here. If I give you nothing to work off of, expert like you should have, like, I'd be like, oh, Jason missed this and he missed that. So thanks, man.
Cian [00:28:58]:
I was like sitting here thinking about, like, what should I mention? And then you just kind of kept taking them right off the list. I was impressed, man. That's great.
Kaisha [00:29:06]:
Blinding the Jason Van Leuven. Blinding the grummies with science since 2021. We appreciate it. So good. Amazing. Thank you both so much for your insights into that. And Dustin, keep us posted. Good luck.
Kaisha [00:29:17]:
All right, we're going to keep it moving. Oh, let me reveal the poll. That's right. We. We have a poll going on YouTube right now. So we asked folks to shout at their location. We got 10% representing Central US, 10% representing the West Coast. We got 40% representing the East coast, and 40% are overseas.
Kaisha [00:29:35]:
So amazing. Welcome to the pie job. We're so happy you're here. Thank you for dropping your questions. Just glad you're listening too. All right, we got this question from Indiebuds. They wrote, when a strain is not performing in our setup and you know it can deliver, how do you know where to start? Changes? Is it VPD changes, nutrient mix, lights, how to know what to adjust and what plants want? This felt like a good connection to your last. The last question.
Jason [00:30:00]:
Oh, fun question. Yeah. So where. Where do we start? Well, I always start with the records that I have. So do I have any growing information about how this plant behaves? Is that maybe previous growth cycles that I've taken, written documentation on, maybe digital, hopefully data logged documentation on growth? Do I have any connections with someone else that has grown it or possibly the breeder that grew it? Those are the places that I like to start because they at least give me some direction on being. All right, well, do I run a. Do I run a. Run a longer, specific type of crop steering strategy? Do I just want to, you know, marginalize how hard I'm pushing these crop steering strategies? You know, and then if you don't have any of that, I like to look at plant height and just morphological behaviors.
Jason [00:30:54]:
If we have a plant that is growing more. More stubby, more stocky, you know, you know, lots of whiter, lower leaves, then, you know, typically I'll push it slightly more, more vegetative, or I'll just cut my generative type of crop steering phase off pretty early. So I think, you know, like Mac1 and Blue Dream, I have been talking about these two. As for probably three or four years as my example, simply because there's about as far on the spectrum as any of the strains that I'm familiar with. And so I was talking about, you know, maybe it's a shorter stock, your stubbier plant, fatter leaves, a little bit lower under canopy growth. Yeah, I'll just not do as long of generative steering. I'll just push it more vegetative. Right.
Jason [00:31:41]:
And so I always have intensity and duration. When we're talking about that earlier I was talking about, you know, lcg, where, you know, my intensity will just be less either way or the other for almost the whole duration. For something like Mac1, I like to give it a little blip of hard generative just to get those flowers set. And, you know, that might be five days, 10 days max. On the other side of the spectrum, if we know this plant's morphological representation is more of a sativa type than classic sativa, everything now is so crossed and blended. I don't know that those are appropriate. But if we go back 10 years and you think of a sativa plant and that morphology, then yeah, let's run generative longer. Right.
Jason [00:32:27]:
So look at plant height. If you can document that through obviously the first day of flower to probably week four, see if you can get two to three readings at the minimum week, that'll at least give you kind of, kind of a curve to work off of. Hey, when does this plant start to in stretch? When does it in stretch? And that's when I try to match up my vegetative type growth. So if you're not, if, if you didn't do that on the last run where it didn't perform, maybe you have that data to work off for the next run. Right. If we kept running generative even past stretch, then let's tighten that up a little bit. If we ended generative too early and we saw. All right, well, shoot, the first day I did vegetative, I saw inch and a quarter plant growth every day.
Jason [00:33:14]:
Then, yeah, let's keep running generative a little bit longer. Right. So try to categorize it and a little bit what I would consider traditional morphological categories and see how it goes. Best thing you can do is document and then compare some of those results to the documentation you have.
Cian [00:33:33]:
Yeah, crop registration. Absolutely. Key man. Be able to go in and just document those changes over time so that you understand what am I doing? What did it result in? And if you are going to try to make changes, ideally having data flows to look back on to be able to make it or change decisions from is going to be the strongest position to be in so that you're able to understand from a, you know, threshold by threshold perspective on your space what resulted in what you're seeing. Jason's example of Mac is a great one. The first time I ever grew a Mac1 strain, I ended up treating it very similarly to a sherbhead plant that was growing next door, and that was a terrible, terrible mistake. The Sherpad plant loves to be run super generatively and the Mac did not appreciate that one bit and ended up very stressed out by the end of week three because I had been pushing it just way too hard through that early generative stage. And in future rounds when I was looking back and trying to grow Mac again and looking back at that data, it was really clear.
Cian [00:34:46]:
I'm like, oh, I pushed the same way I did on this other strain that loves that generative steering strategy. And it really seemed like the Bud production, it got started quickly, but then everything didn't. Didn't really have the strength to grow big during its vegetative bulk stage. And it seemed like that was common across every Mac plant in that room at the time. And the next time I grew it, I kind of what Jason said, I backed off on the gas pedal a little bit there and I did much better that round with it. And then proceeding rounds started going a little bit more similar even to what Jason said and actually barely doing much generative steering with that strain at all and allowing it to move pretty directly into its vegetative steering after, you know, Bud set had started to occur. Because if I pushed it much harder, I was getting proportionately more loose airy buds every time I did that.
Kaisha [00:35:57]:
We are all about the crop registration around here. All right, well, thank you Indiebuds for your question. And I actually have another one related to crop registration here. From our Grow Me Iron Armor, they wrote growing Girl Scout cookies and getting smaller top nugs and bigger bottom nugs. What are the main crop registration points to focus on to help get a better understanding of why this is happening? Mikey mentioned this a little bit last episode. Maybe feel a little better that I'm not the only one getting smaller top nugs than my bottom nugs when growing Girl Scout cookies. What do you guys think?
Jason [00:36:29]:
I just got a shout out here to Iron Armor. You guys don't hear me talk about members of the show very often here, but he's been watching for pretty consistently here for since almost the beginning. You know, one time I was at a client Facility and chat with Guy and he's like, I'm Iron Armor. I was like, yeah. So super glad to see you in here asking questions.
Kaisha [00:36:50]:
You actually met Iron Armor. That's so cool. But yeah, for real, Iron Armor's been with us from the beginning.
Jason [00:36:55]:
Super fun. Yeah. With Girl Scout Cookies. Smaller nugs on top than on bottom. And I guess some of this kind of comes down to density as well. Are they smaller on top because we're seeing better density. The lower ones are lar. You know, are you seeing your best buds through the.
Jason [00:37:15]:
The middle section of the canopy? Kind of a. Kind of a generic boring answer. But canopy uniformity is. Is. Is really the only thing that go for here. Sure. There might be some genetic susceptibility more on a Girl Scout cookies for this where, you know, it's not transporting some of those nutrients and chemical reactions across the plant quite as evenly as some others. But the best thing that you could do there is canopy uniformly.
Jason [00:37:45]:
Right. So when we think about, all right, do we have good airflow through there? Do we have good lighting? You know, whether that be we need to leave more, change our plant spacing or, you know, introduce something like under canopy lighting, maybe we need to turn down our lights above and do canopy lighting. Really, if we want the best performance out of all of the plant, then we have to have ideal parameters and have it uniform across the canopy itself. Right. In both horizontal span and vertical span.
Cian [00:38:25]:
I'm gonna say I've experienced the lower or the smaller bud on top. Well, now, Jason loves to say this strain dependently, that's been one of the ones that I've actually seen. You know, some plants on tray A, some plants on tray B, the plants on tray B end up with smaller nugs on the top of it and are pretty similar height, pretty similar feeding schedule and irrigation strategy. But at the end of the day, the one of the strains really seemed to morphologically make a lot more canopy density around the bud sites around the top, which is more or less what I expect. And then as a result, there was not enough space for a lot of those buds to grow all that much larger. They weren't just bulking out and became these huge colas like the strain next door was. And, you know, maybe some of that's to do with my feeding strategy at the time with those. There could have been some other environmental factors.
Cian [00:39:26]:
But by and large, all the other major things that I was documenting at the time were pretty similar. But most of what I was paying attention to at that period of time Was, you know, like my leaf surface temps around that height in the canopy. Trying to document the density of the canopy, kind of what Jason got to. With the, the uniformity of your canopy and like both light and airflow, being able to get a good mix of temperature homogenization across that, that canopy, all those things are important to be able to take into consideration when you're looking at, you know, factors that are playing into those morphological changes.
Kaisha [00:40:10]:
Awesome. Thank you guys. And Iron Armor, thank you for, for your question and, and for, for being one of the Grammys. We appreciate you. All right, moving on. We've got more coming in on YouTube. Okay. We got this one from Justin.
Kaisha [00:40:23]:
They wrote, I always understood that higher bpd greater than 1.4 stresses the plant and causes them to close their stomata. However, I've seen grows that have BPDs much higher with people running in temperature in the lower 80s with humidity in the lower 50s and 40s and it seems like their plants are doing fine. So please, can I grow just fine with a high bpds, I'd.
Jason [00:40:48]:
It's weed. You can grow just fine in almost all parameters. But the, the details come and do what is fine. Right? It is fine. Keep us in the position in the market where we're a competitive high quality grower. I don't know the answer for you there. It depends on how good your branding is and how picky your customers are. But sure that there's.
Jason [00:41:13]:
There's really no argument. The science is there. And, and actually Dr. Justice, over with the hit mine and CRC, they did a pretty cool study with Licor. Look it up. I was just sharing it. It's been out there for a couple years and basically they just plotted stomatal conductance with some other variables. Right.
Jason [00:41:34]:
So when we look at what stomatal conductance is, obviously it's. Here, we'll show you. We'll get drawing here because we haven't drawn anything all day long. Let's go. And then I will. We'll start on this side and I really should be using the computer and sharing with you guys, but we'll see what I can do to draw stomates.
Kaisha [00:42:17]:
We love a drawing.
Jason [00:42:20]:
Forgive me. Yeah, so obviously, you know, on this side we've got a really well closed up stomate. I should put three of these. This would be like ideal vpd. Right. And so we're getting as much carbon exchange with the plant as we possibly can. Obviously when our stomates close up a little bit, then we're not getting as much Carbon exchange. And obviously carbon is the building block of most plants, so we want as much carbon exchange in there.
Jason [00:42:51]:
When we talked about the, the equation there, you know, CO2 plus water, you know, are our equations going to be based on how much CO2 we can get in there? So the more CO2 we get in there, the better chance our plants are to growing to the amount of water and to the amount of light that's given to them. Right. For photosynthesis, like that's where our building blocks come from. Yes. You know, there are secondary photosynthetic activities that are happening based on available nutrients, based on lighting spectrum, all that types of stuff. But in order for, you know, the first, the first chemical reaction to go on, we gotta have these stomates as open as possible. So here's our basic chart of vpd. Obviously, when our VP is low here, for example, then our stomates are going to be more like the closed side.
Jason [00:43:49]:
They're not exchanging as much gas. When we get to VPDs, say between one and four, if we want a wide range specifically for cannabis, this is different for other types of plants, then our, our stomates are going to be maximized here and that's where we want the most gas exchange as possible. So when we're thinking about building the highest amount of plant mass, you know, we have to be optimizing that stomatal conductance. Our gas exchange needs to be maximized now, and we get VPDs are a little bit high then, you know, maybe, maybe for some strains, none that I've worked with really, you know, 1.6, 1.5, maybe that's where they're at. Like I said, you know, these biological factors aren't as well defined as just us telling you what the answer is here on the tv, computer, phone, Spotify, whatever, you, however you're receiving this information today. But yeah, you know, if it is the fact that, all right, well, maybe we're getting up here, basically, that probably means that some other, some other parameter in your grow could be optimized to get better results. So can I tell you that, hey, that's the wrong thing to do? No. Can I tell you that you may be able to achieve a little bit higher revenue for your company if you do hit those ideal VPDs? Yes.
Jason [00:45:17]:
Can I tell you exactly what that VPD is? If you take a stomatal conductance meter into your grow and start taking measurements, I can help you tell what that, tell you what that answer is. Otherwise, I'm here recommending being at about 1.2 towards the end of flower.
Cian [00:45:34]:
That's a really good way to put it.
Jason [00:45:36]:
Yeah, 1.4. If you're worried about the multiple dues.
Kaisha [00:45:39]:
Yeah, wonderful. Okay. Justin also dropped this additional question which I think, considering what we're talking about would be a good one to tackle is wondering, does running high humidity during mid late flower along with higher temps cause airy buds if mold wasn't initiated?
Jason [00:45:57]:
Not necessarily. That'll be the shortest answer of the history of Arroya.
Cian [00:46:05]:
No.
Kaisha [00:46:06]:
In the history of 127 episodes. Amazing. Okay.
Cian [00:46:11]:
No. But it definitely can be a fine line to walk with those molds and mildews. So be careful there.
Kaisha [00:46:18]:
Always, always be careful. Okay. All right, Justin, we appreciate your questions. Thank you for that. All right, we got this one from Kroni. They wrote that they're growing in coco, feeding daily at 6.0 ph around 1k ppm and flower runoff ph drops to 5.1 to 5.2 despite 20% runoff. Last run I overcorrected with too much flushing. What's a better way to manage runoff Ph?
Jason [00:46:46]:
Hey, it's kind of a theme here for today. Get started with it. We'll just wrap back around to what we were talking about. Obviously, you know, PH being. And I can bring up the slideshow if you guys want here. Maybe, maybe we'll put a little.
Kaisha [00:47:03]:
Give the people what they want. Jason.
Jason [00:47:07]:
Just surprised I haven't worn this PowerPoint point out yet here. But yeah, we're, you know, we're looking at nutrient composition, right? So anions and balance of cations. You know, that is a traditional approach of flushing. It might be half right. Is it the best solution? Absolutely not. You know, really what's happening is, or, you know, if we were flushing in that case, you know, or pushing a lower, no EC feed in there. Really the only thing it's doing is, is pushing the imbalanced nutrients out. Right.
Jason [00:47:44]:
In a much better situation, we just replace them with a well balanced nutrients solution. And so that's where kind of one of our answers this, this beginning of the episode was. All right, you might need to raise your ec, right? So the, you know, the fact that nutrient burning doesn't happen until we're at unusually high ecs, you know, means that, all right, if we want a better balance of nutrition in there, let's just put a little bit more nutrition in there. And so let's get ph up and get it shared. Give me something to work off of here. All right, Share my screen substrate ph. I will actually talk about ways that you can identify what is causing that, you know, that ph change. Specifically when I say what I mean, which element is being accessed or usually it's deficient, like I mentioned.
Jason [00:48:53]:
Yeah. So here's our anions and our cations, right. So when we feed at say 6.0, right. We. We've added certain types of acids or bases to, you know, basically manipulate it. A lot of times actually when we use our fertilizer, we don't even have to use a acid or base really. Kind of depends on the water chemistry coming in from your water supply, what nutrients you're using in any other supplemental stuff that's going into your fertigation. But when we look at, when I say balance, I should have probably just drawn like a line or a scale between these where it's saying, all right, if we went in at 6.0, then the levels of the cations on the right and the anions on the left are causing us to be at 6, 0.
Jason [00:49:41]:
They're perfectly balanced. Then these are common ones. There's probably other stuff in that fertigation water as well. But if everything's balancing, we'd be at seven. Right. So we're going a little bit more acidic side because we're trying to optimize the nutrient availability uptake to these plants. And that's different for different types of substrates. When we're working in, you know, coco, usually our optimal, our optimal Compromise is about 6.0 for.
Jason [00:50:11]:
All right. These are all available, you know, across the board as max that they could without jeopardizing the availability of another one. And so when our ph is going to be shifting one way or another, it says, hey, this plant is probably eating up one of these nutrients, one of these elemental nutrients more than the other. All right. And it's kind of nice. This chart that I'm showing here is based on. We got some of our macros up on top and then we're migrating into some of our micros. Right.
Jason [00:50:42]:
So obviously npk, nitrogen, potassium, phosphorus or phosphorus potassium right here on the top. Right. So if we are, you know, early flower, a lot of times we see actually, you know, these nitrogens causing those pHs to, to be out of balance. Sometimes when we're the flower, the plants are going through a lot of infrastructure growth. They're using a ton of nitrogen. And then, you know, later in flower, we might actually see some of these, you know, potassium and phosphorus just being imbalanced. And so if you send your plants in for leaf tissue analysis, let's say you're getting, you know, a severe imbalance that is causing jeopardy or plants or you are that type of grower that's really kind of got everything dialed in and you want to take the next step. For a specific strain.
Jason [00:51:30]:
You can do some leaf tissue analysis and that'll give you results on what your concentrations of these elements are in the plant matter itself. And obviously that'll show you which ones are elevated, which ones are in demand. And then you can start playing either with creating your own nutrient recipes or, you know, just raising your ec. Like when we talk about just raising your ec, that's, that's just hitting the problem with a hammer. Right. We don't know exactly what the right solution, what exact elemental nutrient is in deficiency. But if we just give it more of everything, then hopefully, you know, that's going to fix that imbalance. We know it'll do a better job fixing the imbalance than giving it less of everything.
Jason [00:52:14]:
But pushing out the imbalance like a flush would do.
Cian [00:52:19]:
It's a great way to say that it's not going to be an exact science trying to get yourself back on track when you add more. But you do know that you're not going to be restricting the nutrient uptake by washing everything back out of it and then trying to build back up from zero. And like Jason said, you know, you're not going to burn the root systems by adding that, that initial feed EC a little bit and trying to give the plant more of what it's already seeming to go through. So, yeah, raise your feed ec.
Kaisha [00:52:56]:
All right, thank you guys for that Crony. Good luck. Thank you for your question. All right, I want to try to get as many of these live questions in as we can. We got this one from Dr. Ropotnik. They wrote they're growing in 1 gallon coco brix, but thinking of switching to 3 gallon and worried about how to maintain a steady dryback with the increase in size. What tips would you guys recommend?
Jason [00:53:21]:
That's very valid concern. If you are an indoor production grower, probably wouldn't go to a 3 gallon, unless for some reason, you know, if you have a very well constrained plant count and you want to grow eight foot plants, then all right, let's go to a three gallon. If that's not your case, then I might stick with, you know, one and a half to two gallon for the size of plants that I mostly prefer to grow. And that's, you know, four and a half to six foot type of plant. You know, one and a half gallon is a really sweet spot of substrate size. And you know, as far as maintaining those drybacks, yeah, it's going to be a challenge. And you know, as we mentioned so much on this show, if you're shooting for a fairly steerable substrate, then, you know, we have to compromise that on something that'll hold more than how much our dryback is, but not too much that we can't make some EC manipulations based on how much we're runoff that we're pushing. Right.
Jason [00:54:25]:
We want, we want our ECs to go up if we're not getting any runoff. If we're, you know, if we're trying to basically stay generative, then we can stay generative. If our substrate's too small, we have to add some vegetative shots or we've pushed more runoff than we want to a lot of times, both those things. But if we're in a three gallon, then for most grows that's a little bit, a little bit larger than I like to be. Like I said, unless you've got a plant count that's restricting you or you're outdoor. But you know, for, for indoor closed grows without plant count constraints, you know, usually that's a little bit, a little bit larger than we want to be in.
Cian [00:55:08]:
Yeah, I'd say the same thing. You're going to have a harder time being able to have the consistency that you're looking for with regard to your dryback windows on a daily basis. And the other thing is you may end up needing to run those plants longer to make the most of having everything in a three gallon pot. Kind of like what Jason was saying. You know, when you do that, oftentimes you're restricting plant cuts or that's maybe the reason that you're running such a large substrate in the first place and trying to get a bigger canopy out of it, if that's what you're doing. You know, there are cost bend costs and benefits to doing that. One of the major costs is just more time. You're going to have to invest more time into vegging those plants to be able to get them to the stage of development that you really want them to be.
Cian [00:56:01]:
Which, you know, in this industry, the further past 65 day flowering window you really get, the less competitive it is for you to really be growing that strain at scale.
Kaisha [00:56:16]:
All right, on you guys, thank you for that. And to Dr. Ropotnik, good luck. Thank you for your question. All right, you guys, we're gonna, we only have a few minutes left. We got this question on Instagram. What percentage on a moisture meter should I be looking to achieve when drying the product before it goes into boxes for cure? And I know I just read a story earlier this week on Marijuana Moment about, about the National Institute of Standards and Technology updating industry standards for the level of moisture. But I want maybe this is a good chance for us to give folks a little bit of overview of what they should be taking into consideration at the drying and curing stage.
Jason [00:56:53]:
Yeah. So let's just kind of start off with the definition of drying versus curing. During drying, I'm actually trying to drop those moisture contents in the plant right when we start with, we're going to be typically 85/ percent water moisture content in a growing cannabis plant, living cannabis plants. When we cut it, that's basically what it's going to be at. And we're going to try and, you know, achieve the probably 12, 15% moisture content there by the end of drying. There's going to be some caveats that I'm going to talk about here in just a minute, but when we go into curing, for me, ideally curing is not changing how much moisture content is actually in my product. Right. So in my care room, I want it to be the humidity that my target water activity is.
Jason [00:57:41]:
And ask the question asker here, the submitter is going to be like, oh, I didn't talk about water activity or humidity. I talked about moisture content. Well, these things are all important when we're trying to hit those, you know, moisture contents and you know, moisture content is probably not the best number to use. Water activity for me is a little bit more accurate, a little bit easier to use because I am perfectly related to the humidity of in my environment. So if I have, you know, a product that comes out at 0.6 or let's say 0.55 water activity, I leave it in a room that's 55% humidity. I could come back a long time later, still going to be 55% or it's going to be 0.55 water activity. That 0.55 water activity is also, you know, matching the humidity in the room. Right.
Jason [00:58:29]:
So when we're at 0.55 and 55% in the room, we're at equilibrium. There's no water transfer to the environment to the room. There's no water transfer into the plant or into the dry bud. Now that we've defined those two stages. So if you are in that situation, then you just need to think about what does my end product need to be to be most Sellable, Right. Am I somebody that's supplying quarters and halves, ounce bags to people that are rolling a lot of joints? I want my, might want my product a little bit drier side simply because, well, I can get higher THC numbers if it's drier, but also because that's a little bit easier to process for the end user. Maybe I'm rolling joints internally a little bit easier to process. If I'm going into premium jars, you know, I might be want to be a little bit higher in those moisture contents.
Jason [00:59:26]:
Basically where I start with is thinking about, well, what do we got? We got a minute. Let's talk about isotherms. Basically, when we think about moisture content, we also have to identify and water activity. I know this is all about moisture content, but for me my brain always thinks about water activity. Isotherms look like something like this. So let's go water content. Water activity. Right.
Jason [01:00:06]:
So we can basically chart those two together and at some point for a specific type of product, you know, we can always predict either water activity or.
Cian [01:00:16]:
Or.
Jason [01:00:19]:
Moisture content, water content, moisture content, whatever, you know, based on the isotherm. So that's a relationship between these two for a specific product. There are some published things for generalized cannabis and you know, as far as, how do we achieve that? Well, yeah, dry your product to the moisture content that you want and then obviously if you can process it and store it in an environment that, that that is the same water activity as that moisture content that you wanted, then you can guarantee that that's what's going out the door. Right. So a lot of times it's gotta be four or five dozen clients that I've worked with and they have just come back with very positive things about having climate control in their processing rooms. You know, the fact that it takes the strain off them to make sure the product gets processed quickly or put back out of the processing room. Yeah, just climate, climate control, your process room so that you're at the humidity, you want your water activity in those plants to be right. And the longer we leave it in there, the closer it actually gets to where we want it to be.
Jason [01:01:26]:
Yeah, see and go.
Cian [01:01:28]:
I guess that's a great suggestion. Just make sure that you're, you know, watching that when you are thinking about your processing. If you don't have a climate controlled processing room, you know, you may be over drying in there in a way that you aren't really catching if you're not tracking your water activity. Like Jason said, you know, playing to your market's a big Part of this, because some people may not want to buy your product at certain water activity levels. However, you know, the trend right now, it seems like, is that 0.55 mark that I've talked or that Jason was talking about earlier, that seems to be kind of the sweet spot for most producers these days because it's well under the level you're going to have any microbial issues, develop, developing any botrytis or any sort of molds, mildews on the, on the flower. And you're also keeping your water activity high enough and at a stable point where you're not going to have as much moisture exchange with that cannabis as it sits. Like Jason said, in stable shelf life, you're going to have a much, much wider selling window if you're able to control that moisture activity rather than just looking at it through the lens of moisture content. So the other thing to think about that I think a lot of people kind of overlook is that when you, when you tend to measure things kind of by the mixture of moisture content and the old, like, snap, the branch method, I was really surprised to find that I tend to estimate on the drier side of things, which you leave a lot of money on the table by doing that.
Cian [01:03:12]:
And it's worth understanding that at scale, if you are able to come to market and package a product that is, you know, at 0.55, you're going to have essentially a higher yield than you would have packaging at, you know, 0.4.
Kaisha [01:03:37]:
Bam. All right, with that, we're done, y'all, for the day. Thank you so much, Jason and CN for holding it down and covering all these wonderful questions. Thank you, producer Chris, as well for another great session. And thanks to all of you for joining us for this week's Aurora office hours. To learn more about AROYA, book a demo@aurora IO and our team will show you the ins and outs of the ultimate cannabis cultivation platform. If you have any crop steering or cultivation questions you want us to cover, we didn't get to your questions today. Drop them anytime in the AA app, email us at salesroyaa IO or send us a DM.
Kaisha [01:04:09]:
We're on Instagram, Facebook and LinkedIn and we want to hear from you. If you're a fan of the plot of the pod, please leave us a review on Spotify, Apple Music, YouTube or wherever you listen to your podcast. We appreciate your feedback and be sure to subscribe to our YouTube so you never miss an episode. Thanks, y'all. See you on episode 128.