In the Weeds • August 12, 2021

Electrical Conductivity

Speaker 1:

All right. So I get one take at this. I hope I do a good job because there's no real retakes because I can't just make the whole process happen over again. Yesterday we were cleaning in here, I knocked over this tray, so I had to do this all over again and that's why I'm wearing a different shirt. So what I did today is I used the lid to cover the tray that I'm doing all my catch water in. This will ensure that I don't have any evaporation because I saw a few comments about, how are you going to prevent evaporation? I put a lid over my catch tray and that's how I prevented that. My last irrigation went off about an hour ago. Right now, according to the ProCheck, I'm at 35% water content and 9.51 EC. That's pore water EC.

A lot of people have been talking about like, oh, wow, substrate EC getting too high, this, that, and the other. If you look at any of my videos or see anything, you can see my plants are pretty healthy. These plants really look great to me. I don't see any issues with them, very strong stalks. I'm happy with the structure of them. I'm running a higher EC because I've been having lower light lately so I'm trying not to get too much runoff. This helps with root pressure. The lower your light levels, the higher your substrate EC should be. The higher your light levels, the lower your substrate EC should be. Not always the case, we've found a lot of different things that are leading me towards the fact that these plants can handle a ton. So seeing a 10 EC, basically 9.5 EC in my substrate, I'm not bothered at all.

Typically, in here we're getting about 1,500 to 2,400 micromoles. Don't know what the DLI is, I just got my DLI sensor from AROYA, so I'll be installing that and then capturing exactly what the DLI is in the greenhouse so that way I have another data point to look at. Yeah. So what I did for anybody that didn't catch the other video is I did a runoff check and I'm going to be recording what the runoff check is. We're first going to check and show the difference between your feed EC, your runoff EC, and your substrate EC. So we know the substrate EC is 9.5 right now.

I'm going to check what the EC in my feed is. It shouldn't be around a 2.0, it's a 1.88. Lately I've been running a little bit lower just because I've been having to feed so much. Today's a little bit of an overcast day. So what I like to do is when I have really high light intensities, and I'm having to irrigate all day long to maintain a good substrate temperature and keep it saturated, I tend to reduce my feed EC because I'm just running through nutrients. Now, today was an overcast day and yesterday was an overcast day, so I've actually tapered my feedings back.

I don't know how much runoff I'll have today, but we'll find out. So first step in checking runoff is checking what your EC is and your pH is. Those are two main reasons why you should have a catch cup in your greenhouse or in your indoor facility is, set a catch cup up, this way you always know what's coming out at the dripper. This is important if you're using any sort of fertigation machine. So I'm going to check my pH, it's coming out at a 5.7, that's right on target. And like I already said, the EC is at 1.85. It's a little bit low, so I need to go make some adjustments. I was targeting a 2.0, off to see what happened.

Now, the next thing that I'm going to do now that I've checked what the pH and EC is, so I'm going to write the EC 1.88, pH 5.7. Now I'm going to get the volume. So I've got a measuring cup. It's always important, you want to know the exact volume. So I'm going to go through and measure what these came out to be, so I'm going to take these first ones. I had to do multiple cups plus I added a tray because yesterday when I did this test initially, one, the first tray I had toppled over, so I said, let me put it all in the center and ensure it doesn't get knocked over for whatever reason. But yeah, that's, I need to actually get a bucket that would make it a lot easier, but you know how life is on the farm, you're always just making do with what you got.

So that's 500. I'm going to just mark how many of these I fill. I get to just throw it right on the ground because shit there's nothing wrong with that. So that's another 500, so that puts us at a thousand. There's another 500, so 1500 milliliters so far from today's irrigations. And then, the last remaining bit, there's another 500, so that's 2,000, so it's a half gallon of water today. And the final amount is 180. So that's 180. So that's 2180. All right. So, that's 2180. Now, I'm going to lift this plant off, it's a really strong stalk so I don't have to really worry about too much. And fuck me, there's no runoff today. Shit. Well, it looks like I'm going to have to set this up again and push a little bit higher on my feeds to get some runoff.

Typically, what you see in runoff, I'll talk about this and I'll do this experiment again when I actually have more runoff in the day, I guess I got to pump these plants a little bit harder because they are just charging along. Well, that being said, knowing that my feed EC is a 2.0 right now, and I have a 10 EC, and my substrate 9.5 EC in my substrate, you can see that by not achieving runoff, what's that doing? That's allowing the substrate to build up higher and higher in EC. If I saw any phytotoxicities, or any stress points, or burns on the plant, that's usually my main indicator that I needed force more runoff.

In this scenario for the science of things, I tapered my feeds back because I was having lower light levels these last few days, so that's probably why I didn't get runoff. But a lot of the times I'm usually pushing 10 to 15% runoff. On a normal warm day, hot day, I'm pushing 30% runoff. Usually what I see when my feed EC is a two and my substrate EC, I like to keep in coco between a four and a 10, that's where I like to see it, rookwool between a three and a seven, three and an eight. There's always different things that I like to do. If I'm seeing a plant can handle it, sometimes I have a 15 EC in the substrate. If I'm in a really, really high light intensity setting, sometimes I'm down to like a two, two and a half, 3 EC in the substrate, just because I'm pumping so much nutrients through that, I'm getting like 50% runoff in the day.

Yeah. A lot of the times in your runoff you'll see it even higher than substrate, and then sometimes you'll see it lower than what's in the substrate. It's important to know this because anybody that's just evaluating what's in their substrate as runoff, and then making decisions on how much more to push it, is kind of making a false decision. So if you see a high EC in your runoff, that doesn't necessarily mean that the EC in your substrate is super high, that is why having a substrate sensor that measures pore water EC is really, really important. So like I said, I'm using the TEROS 12 from METER Group. I really like that.

I have AROYA assistant here where I'm managing all these things, seeing a 24-hour spread of what's happening with your water content and EC really allows you to make these decisions. And that's a big reason why we do what we do is, we're constantly trying to control what's happening in the substrate. It's always important to look at runoff values. I think it's always a big thing to see what's coming in the runoff. Runoff pH could also help tell you what nutrients your plants are uptaking. But yeah, the main goal of this test was to show that your feed EC could be lower than your substrate EC, and your substrate EC could be lower or higher than your runoff EC. I'll do this test again. I'll set it up in a room that I know for sure I'm getting a lot of runoff in right now, and we'll readjourn to show what those results are.

I hope this video is helpful, it is brought to you in part by METER Group. A lot of what we're doing is really trying to push science and data behind cultivation. No more broscience. There is a lot of things that I've learned through observation, but I like to bring it back to actual numbers. Don't freak out if you buy a SOLUS and you see an EC of a 12 or 15 in your medium, that does not mean that you have to flush the plant out.

I never recommend using just flash water on your plants. What happens is, you're going to drive the EC down too quickly, you're going to deplenish your plant of available nutrients then causing it to have deficiencies. So if you're ever seeing a high EC in your medium, and you're seeing signs of stress on the plants, utilize runoff, percent runoff, to control the buildup and breakdown of EC. I tend to not want to drop EC, substrate EC, at peak water content more than one to 2 EC in a day. If you drive it down too fast, you're always going to have a really regenerative effect on the plant. Remember that a high EC in the substrate is going to be more generative, a low EC in the substrate is going to be more vegetative.

In the case of my plants, I'm really trying to push generative cues. I've really been tapering off irrigations, driving these cues to set flower in and force them to flower. I am growing in a greenhouse without a [deprecating 00:11:33] system, so all the generative cues I could give will help drive it to flower earlier. I know they are photoperiodic, but you can do little things like this to help push the plant over to one side. So stressing the plant might make it flower earlier than if you didn't stress the plant. And I think that having an understanding of how to manipulate what's happening in the medium is really key. So in the case of me having a 2 EC and a 9.5 EC in the substrate, if I wanted to lower my substrate EC, I'd force more runoff, that's going to lower the EC. If I want to build the EC up, no runoff. As you can see, my substrate EC is higher than my feed.

Yeah. And that's all the main principles of what I was trying to go over. I hope this was helpful. I really couldn't do it any other way than a live feed, so I know I rambled a little bit, but if you appreciate what you see, follow us, like our feeds, go check out my Cannabis Trading Co webpage. We have a lot of product that we've been growing here on the farm, on the site. You could see how our product actually turns out, see the process, what we've been going through here. I will be doing a video soon on installing a full AROYA system. That will probably be happening over the next couple of weeks. I'll be sharing what's happening with my graphs and the data, so that way you guys can kind of see what's happening live time with the real cultivation.

Yeah. That's about it. Thank you guys so much. Hope this was valuable. Fill the comment box with questions and I'll do my best to answer them as I get time. If I don't respond to DM, by the way, it's just because I get hundreds of them in a day. I'm one person, I got to work for myself so I got to make money first with the jobs and people that pay me, and then when I do have time, I answer the questions. So wish you all the best, happy growing, talk to you soon.



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