BuildASoil: Day 21 Flower Update // Spectrum Tuning, PPFD Adjustments & Super Cropping

Episode 06:Spectrum Tuning, PPFD Adjustments & Super Cropping

We’re back inside the 4×4 Battle Tents for Season 2, and today marks Day 21 of flower. This is where spectrum tuning and canopy management become critical for maximizing plant health and flower development.

In this episode, I take you through root growth observations, watering system updates, and the first stages of defoliation prep. You’ll see how I adjust the spectrum tuner settings, measure PPFD levels across the canopy, and fine-tune light intensity for optimal results. I also cover super cropping techniques for even canopy management and share important reminders about airflow and humidity awareness as plants push deeper into flower.

This episode wraps up with a look at defoliation plans and how environmental awareness ties into keeping your grow healthy, balanced, and thriving.

Disclaimer: This content is for educational and informational purposes only. BuildASoil is dedicated to teaching the art and science of soil-based growing. Always follow your local laws and regulations.

TIMESTAMPS
00:00 – Intro
00:32 – Day 21 Flower & Spectrum Tuning Insights
05:57 – Root Growth, Watering System & Defoliation Prep
10:39 – Spectrum Tuner Setup & Light Adjustments
13:36 – PPFD Measurements & Light Dimming
17:44 – Super Cropping for Canopy Management
19:32 – Defoliation Plans, Airflow & Humidity Awareness

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Music: Rebel by LionRiddims

Hello and welcome to another build YouTube episode. [Music] Today we’ve got our Battle Tent season 2. We’re on episode 6. It’s day 21 of flower. And I want to get in here and show you because the last episode it looked like the plants were about the same size and that was on day, I believe 14. That Monday when I came in, it was dramatically different in here. And so obviously there’s only so much the light’s going to do as far as the phenotypic response that the same genetics are going to result in. And so if you were to put very little light or change the spectrum of light, it could change the results on how the structure looks. And so for this battle tents, not only are we looking into the quality of the lights and seeing how they work, um, but the spectrum tuning, it’s been one of these things where it’s like, do you even need that? And while I don’t think the average grower needs to go buy a spectrum tuning light to control stretch, it was a way for me to say, “Hey, I could try that. My GMO is stretching like crazy. Could Could it work?” And it it worked. I think clearly using the light on that spectrum would help. But I think still what you can’t do is throw away the basics. And the basics would be keep it a little smaller before you flip. But for the basic growing system where we’re doing blue mat with clean water, we’ve top dressed, we’ve put the root wise in, we’ve shown you the basic build a soil away protocol as hands-off as you can get. And look at the results we’re getting. So come in here where you can see a little bit better on the camera. I know the light kind of skews it. We’re going to be changing the spectrum in here for the first time. So we’re actually going to use the spectrum tuner on camera today. I just want you to see what it looks like. Now, this one has not hit the top on any of them. I’ve left them completely untouched. I pinched a few before I put this layer of trellus on, but they stood back up on their own. And I didn’t do anything else since then. The tallest one is back here. It’s remained that tall for since Monday. It was maybe 2 in lower at the most. It’s gone up a little bit since Monday, but it’s basically done stretching. It’s now ripening. It’s like now stacking in here. We’re come over here. Most of these were through the light, so I had to bend them all. And so now you’re seeing some of the lower ones start to shoot up, which is great. That’s what we want. And so I’m going to go over there and be able to manage the canopy on the other side. But before I did that, I just wanted to show you how much taller this one was and all the bent plants. They would have all gone through the light. So I bent them all early and this thing still shot up in areas across the back. Whereas this one just held the stretch all the way through. Um it didn’t hit the light anywhere across the board. And I didn’t have to bend any of them where a lot of those that are up I already bent and they stood back up. And that’s why um it looks a little more even right now. I swear in between here on social media, I was posting the differences. So, you can check out our Instagram. On Monday, I was like, “Wow, this one stopped and that one’s still going. What are we going to do?” And literally then I had to start bending them or they would have been through the light. So, I’d say what happened as far as a result from what I’m seeing is that this finished it stretch faster. So, the same amount of energy was put into the stretch. Um, but this one seemed like it started crowning a little bit sooner, started going into the stack a little bit sooner, and stopped stretching a little bit sooner. Um, otherwise the health across both look really, really good. Um, it’s kind of hard to tell the difference. The other thing that I will say, when I’m looking in here, it’s hard to tell. When I took pictures, you can’t really tell, but when I’m looking in, it looks like I already defoliated a little bit. Where over here when I’m looking in, not this area cuz I’ve supercropped. It’s kind of it it’s more clustered because of the bent ones. But in here, I’m seeing more leaf material. And so, I just think the difference in spectrum, I actually grabbed a couple of leaves and picked them off and looked at them next to each other. It seems like on this side, all of the leaf material is slightly elongated and a little bit bigger. And so, that might lead to the appearance that it’s more full of leaf in here. Um, otherwise the node spacing when I measure it and look at it, it’s slightly tighter on the left side, which follows what you’d expect under the more blue dominant full spectrum lighting, but it’s not double triple difference or anything crazy. And so I really think that if the future of spectrum tuning gets a lot cheaper, it’ll allow growers to have more fun and really maybe dial in their specific genetic to be exactly as they want. And you could even utilize some of these texts, so to speak, to say, “Hey, this one really is stretchy, so I’m going to be a little more blue dominant. It will help me.” Um, this one doesn’t stretch at all, so I’m going to be more red dominant. Hopefully, I get a little bit more stretch out of this bushy plant, and maybe that’ll give me some more yield. And so, I think as we all get them, as the technology and the price comes down, we’ll all come up with new ways to make them work for us. But right now, it’s a tool and I’m fascinated with it. I just don’t think everyone has to have it. It’s clear that with a regular light, you can also get good results. But what I promise to do is even though we’re through the main phase, I’m about to activate more spectrum there. I still am going to report back about any differences that I see in quality or whatever else. Um, the main thing that I like about this one so far is just wall to-all even. And it’s just a beautiful light. And when I call Thomas at Grandmaster, he answers my questions. When I have an issue, they immediately answer. And it feels like they’re passionate about what they’re doing. And so it makes me really want to support brands like that that are into the data and into making the best they can possibly make it. And the lighting world since all the tariffs and all the things happening, it’s like shook up. It’s like you’re just getting the same kind of lights from China. And so I feel like Grandmaster is innovating and doing something different and I like supporting that, right? So that’s part of why we’re doing it. Let’s get on with it. Let me show you underneath what’s going on. Look at all these feeder roots down here. Not sure if you can see that on the camera, but there’s a lot of feeder roots right there in that area. and they’re coming up because they’re trying to access this drip tape which is just slowly dripping right now. And it’s crazy because there’s only two drip tapes in here, but it’s it’s moist all the way across the surface. And so I’m going to come in here and I’ll probably add a little bit of more top dressing. Um, but everything looks really good in here. Same on this side. I threw a couple leaves on there, but underneath here in this area, you can see fer roots kind of coming up. Maybe a little harder to see on camera, but this is all I’m doing. It’s literally set on the red mark preset from the factory. I haven’t adjusted anything and it’s working exactly as you’d expect all the way through. I mean, the stock, it’s impressive. It’s like a tree. I know I’m bringing you back down here, but I mean, it’s bigger than my thumb by a long shot. It’s barky. I haven’t topped this plant once. Both of them are filling the entire tent. One plant. And the water is just coming from right here. In fact, it’s already right here. I need to come fill it. And so on Monday I filled it and then on Wednesday I filled it and now it’s Friday. So it’s been pretty consistent every two days going through that thing. That’s about to slow down now that the stretch is stopping. But you know that’s that’s 13 gallons. There’s probably a few in the bottom. So it’s going through five gallons a day right now. 2 and a half gallons per plant which makes sense cuz what do I teach you? 30 gallons of soil max watering through stretches. Three gallons of water. It’s almost doing that daily. It’s kind of wild. But 2 and 1/2’s a little less, which means it’s a little less than 10% that it’s pumping through. And it’s not all at once. It’s slowly slowly drip through the system. So anyways, I’m just having a ton of fun. What we have to do next, that’s actually going to be the first bit of work I have to put in here, is go defoliate and remove branches that just aren’t going to do anything. So like for instance, come over here. If you’ve seen my previous videos where I teach, this is more of just a comparison. I go through and show like look at this is never going to make it up to the light. It’s I need to strip that. This needs to be stripped. This needs to be stripped. And I’ll take each branch and I’ll go through and I’ll take everything from below this first screen 100% basically gone. Then I’ll go up to between the the first screen and the second screen and I’m going to strip all of the leaf that I can get access to that is blocking anything and any of the little piddly ones. And that’ll allow much more light penetration to occur to the lowers that I do keep. they get some size on them and that will direct mo more of the energy into the tops instead of growing useless material that I don’t really want. And so all of this just takes energy and it takes that energy and puts it in motion and it puts the carbon, hydrogen, oxygen and all the other material and it’s like a whole concert of things. And the last thing I want to do is put all of that effort into all these areas when I’m growing it for the flower for me. And so I’m just going to remove all of that. When you come in here, it’ll be a lot cleaner. In fact, if you wanted to, you could strip all the way up to probably this top layer pretty aggressively. I do really aggressive under there. In here, I mainly do it for air flow and light penetration, and I don’t worry about being perfect. And then I take off all the little branches that just aren’t going to reach to the top. That allows me to maximize the yield and minimize the trimming. So, that’s what I’ve got to do. What I’m going to do instead of trying to do it all at once, which would probably take me 30 minutes per side or more, I’m just going to start doing it day by day and stripping a little bit here and there. And then I’ll probably put one big go into it. By either the next time you see this or maybe I’ll do a little on video, it’ll be stripped. But today, what I wanted to do is at least show the plants, show the difference in the light before I start pinching. Um, and then I want to adjust the spectrum. And the light’s pretty bright and I’m about to adjust the spectrum. Um, we got given a gift by a company and it just showed up and they happen to be perfect for right now. Um, I don’t know much about them, but they’re going to work right now. So, I’m going to grab this pair of sunglasses from Pakaolo Flies. I guess Black Flies makes them and it’s a brand. And of course, you know, I’m big into Hawaii and Paka Lolo. And so, um, she sent us some glasses for my wife and for me and said, “Protect your eyes.” And since I’m about to stare at that light, mess with the spectrum, I’m going to put them on. Um, and then we’re going to supercrop everything after I adjust the spectrum. So, let me grab them. All right. Now, she sent a couple styles. The first one didn’t fit my face. Looked great on my wife. And the second one is like classic black flies, which I don’t like, but I want to make sure I can see. And so, if you’re into this type of thing, they probably have other styles, but there’s the Black Flies uh bag there since 1991, which when I grew up, you know, a lot of people had the Black Flies. Pretty cool. Um, but it’s helping as I stare in this light. And so, um, I just want to give them a shout out. I have no idea who they are. Um, but my wife’s followed her for a while and they sent us a rad gift. And so, I’m just going to use them while I stare at this light. Okay. Um, let’s grab the spectrum tuner. I’m going to look really quickly at my cell phone and see Thomas told me like some recommendations. And I said, “What do you want me to change it to?” And so, let’s see what he says. 100% warm, 20% cool, 25% deep, and then dim to desired PPFD. I’m omitting the far red because we already have 5% far red in the white dodes. And so, um, that’s the recipe I’m going to go with. So, let’s do let’s do it. Let me show you what it looks like. I’ll keep this right here so I can reference it. And so, I go on the screen. And so, I’m going to go to my timer set. You can see I’ve only got one channel on and that’s triggered. I’m at 53% of all of four of those. And channel one is all I’ve been using, 100%. I’m going to go to the timer set. You can see at 6:00 a.m. Okay, I have 100% channel one and nothing else. And then 12 hours later at 1800 hours everything goes to zero. That’s how I’ve got it set up. So what I’m gonna do is go into here and now I’m gonna adjust this. He said let’s go 20%. Which I can just drag. Okay. 20%. Then channel two I believe is going to be the warm. I got to make sure he said 100%. And then channel three is 25%. Which I believe is that red. So, let’s see. I’ll verify these are the right channels. Someone probably knows and is watching is like, “Oh, that’s the wrong channel.” But I’m pretty sure he told them to me in order. I just can’t tell inside here because it doesn’t say like cool white, warm white. You know what I mean? But 20%, 100% 25%. Okay, I’m going to save that. And now you can see it’s saved there. Okay. The problem is is that’s not going to fire and actually change the spectrum, okay, until 6 a.m. when it fires on again because that’s how it works. So, what I can do right now is just go set it here, I believe. And then in the morning, it’ll reset to what I have the timer set to. So, I’m going to take this. I’m going to do the first one and dim it down because that’ll tell me, you know, the cool white. Okay, so there’s 20%. Now, let’s see if this channel 2 is the warm white. I’m going to go to 100%. Yes. See the warm whites on now. Check it. Look at that. So now there’s two strips instead of just the one. Now you can clearly see the color difference. And I can kind of see because I got the glasses on. I’m still trying not to stare at it. All right. And then channel three said let’s do 25%. So you can see some of the reds come on. So now we’re using three of the channels. Oh, that’s overall. Let me go back. Okay. So 20, 100, and 125. zero on channel four. All right. Now, once that sits for a minute, it goes back to the overall brightness, which now I’m gonna grab my PPFD PPFD meter. We’re going to measure the intensity in here and keep it where I want it. And then I’m going to super crop. So, that’s all we have to do. I can see that in the morning it’s going to fire at that same recipe at 6:00 a.m. And I’ve already adjusted today what’s currently running. So, I’m good to go. Okay. So now I’ve got this. Angle it accordingly. It’s on. We are at 900 a,000. I mean this is perfect at the percentage that it was at. That’s pretty cool. 1,000 even right here underneath it. 1,200. I mean that’s acceptable. I’m still going to bend that one so it doesn’t burn. But like I can actually stay this close to the light. I may not have to super crop in here if I keep it at that percentage. But here’s the thing is down here. Oh, that’s still pretty good. We’re like 550 600. Okay, here’s my thoughts on this. Most tent growers can be 600 and crush their entire flower around. It’s fine. You can be 600 to 900. You don’t need to be in a,000. So, what I’m going to do is allow the tops to ride 1,000 to,100 and I think I’ll be fine because I want the rest of it to be a little bit lower. But knowing that even over here we’re hitting like those numbers. Let’s see what’s that 840. Let’s see the side nug. I mean that one’s really good right now. I would be okay with that. I want to be closer to 600. But I mean even above 500 you’re going to get good quality flowers. It doesn’t have to be that you’re cranking it. Quality a lot of times comes from letting it just do its thing. So um let’s go up just a little bit and see what happens. That’s 60% of all those channels at that recipe. Okay, that’s acceptable. That’s pretty good. Okay, that’s a little bit better. I’m going to keep it there and I’m going to supercrop a few of those that are taller and I think we’re going to be just in a perfect range there. Now, let’s see where we’re at in here. 1300, 1200. So, that’s a little bit too much as we get close to these strips. That one’s pretty good. I know it’s hard to show. You can’t really show everything at once while I’m filming, but let’s see. 1,200. So, right here by this nug 1340. So, I might have to dim it a little bit in here. It’s just that these are a little bit more powerful for how close it is. That one seems to be I don’t know what it is. It just seems to like it’s a little bit gentler while also being very powerful. Probably because of how it’s spread out throughout the entire tent versus a little bit more focused. Um, I’m I’m happy with the results in either side, but I feel like instead of turning this one up now that this is all pretty close, it’s all uniformly a little bit higher in here, I’m probably going to have to dim this one just a little bit. Falls off when you get to the edges, but not as bad. Like that’s 450, right? And so I’d rather it be a little bit higher there, but I can’t turn the light up. Um, so I’ve got the AC infinity here. Let me turn it down a notch. Let me see what setting I’m actually on. It’s kind of crazy how low this thing is running right now. It’s almost overkill for a tent as far as how it’s set up. All right, so 4×4 Cyprus, I’m set on 50% right now. And so that’s why I feel like running 60% of that light, still having one channel open available. I don’t really know what the difference is, but I’m reading the PPFD and that’s all that really matters. So let me just go to this one. Let me see. Down to 40%. Done. I have no sunset sunrise, so it should be pretty much automatic. Let me see where we’re at now. Okay. So now instead of 1350 or whatever, it’s 1150. So I’m happy with that. 960 11 or,000. So I’m just going to leave it. I think that’s good. I don’t want anything hitting 1300. It’s a little too high. I’d rather be like 1,000 to,100. So this light I’m going to be running at 40% to keep it in that targeted range of PPFD. And then that allows me to kind of leave it here. I think still what I’m going to do today is this one was already super cropped, but I’m just going to do it a little bit more. Same thing with this one. And I can go in the other side of the tent and be a little bit more gentle so I don’t push on this. But I’m going to take the tallest ones that you see and I’m going to bend them again just to make sure that we don’t get anything growing into the light over the weekend. So that’s where I’m at. And now that I’ve got the light set, it’s actually pretty good. I don’t have to be too aggressive in here. But I’m gonna go take this one, bend it and [Music] I know when I was brand I knew I hated doing this. I was like, “It’s so perfect.” And now it looks ugly and bent over and everything, but don’t be scared. It’s better than burning them into the light and all that. And realistically, I probably The light’s doing pretty well. I probably could have just left it, but it’s already more uniform. Let me open it, get to the back. I wonder I’ll have to ask the lady about these glasses. Like, does it Can I like I would just use my normal glasses. I’m wondering why. Maybe they’re It says like LED on it. like their special for LED lighting. Not really sure. It looks pretty good in here. Maybe they just the spectrum is like what they’re tuning so to speak through the glasses. I don’t know. I think Grandmaster’s got some lights too or some glasses too. I wonder like what the difference is between the Growite uh glasses and the regular ones. All right, let’s go through this side. Okay, I think that’s pretty good. Uh, next we got to do that defoliation that I talked about. And so when I come in here next time, I mean, I already did a pretty good job, but there’s so many little things that I’m just going to want to like take off, you know, and I don’t want to do it with my hands cuz it would strip that whole branch. But a lot of this stuff will come off. And indoors, you know, it really helps keep the air flow going. You don’t want any mold or mildew. Um it’s just it’s a shitty lesson to learn when you’re brand new that if there’s no air flow and you have it all stacked on top of each other and you’re supercropping branches and you don’t manage the humidity, um it can lead to bud rot. And right now we’re going into monsoon season and it’s a lot more humid than normal. And so right now like I don’t need to run humidifiers or anything. And you just need to be aware of your own environment. Make sure you’re paying attention to the environmental chart and focus on the weakest link. If there’s something you can’t control, just be aware of it. Like right now, higher humidity, not a problem. But if it was deep, deep flour and it was inverted or like at night it was warm in there and stagnant with no air flow, you could get bud rot really really quickly. So you just want to be aware of those things. Otherwise, um that’s everything that I wanted to teach you today. Um I really appreciate you watching. Thank you so much for following along. Um, like usual, if you haven’t done so already, subscribe, like, tell your friends about all these videos so we can teach each other and we can do better. Um, if you have questions, drop them in here. As usual, um, I’ll do FAQs. I know I haven’t done as many as of recent, but I promise I’m going to be doing a flurry of them soon, which means if you want your question answered on camera, put it in these videos, and I’m going to be going throughing through them and answering as many as I can. Um, thanks so much for watching and until next time, I’ll see you on the next Build a Soil video. [Music]