I started having issues show up through the leaves a few weeks ago, all I was doing was ph’ing my res off to 5.8 and not reading EC or PPM as I didn’t know about this. I was getting signs of what I think are ph fluctuations on my leaves.. so I bought a blue lab guardian set up.. my process is as follows now. I keep my coco damp at all times by feeding once a day 2l with about 20% run off and that’s taken away. I mix my nutes (1ml/L up in a 70l so 70ml of each thing I use, apart from silica what is 0.2/L) res and ph that and then I take away some in 5l containers and start adding ph water to my res to bring my EC/PPM down. When I have it at 850ppm and 1.2 EC I then PH that and feed.. my temps are 25c and humidity is 50-60%.. I have three 600w MH lights in a 2x2x2 tent. They are ready to be flipped to 12/12 now but I want to know why I’m having these issues with my leaves?? They have plenty of growth coming through and are taking off but something isn’t quite right? My PH at root level is between 5.6-5.8. Any help would be appreciated.. if I’ve left out helpful information please let me.
On going issues, heeeelp lol.
- Thread starter meerkat67
- Start date
Yeah, it’s done at the same time each day. In my eyes everything is okay but the leaves are telling a different story going by those photos? I don’t really know what else I can do/what the issue is. My PH seems sweet. Drops a couple 1-2 points?
FirstCavApache64
Well-Known Member
Are you really using 1800 watts in a 2x2? If so then I'm guessing that's the issue. I just can't see how you could even fit them. I'm guessing it was a typo.
GreenhouseGreen
Well-Known Member
2x2x2. OP measured volume in Ls and temp in C. I'm guessing the 2x2x2 is in meters. So, a little over 6x6x6. By my math it's a little under 50w/sqft of HID. For comparison a 1000w in a 4x4 is 62.5w/sqft and a 600w in a 4x4 is 37.5w/sqft. Seems about right to me. I don't know how it could be evenly spread, though.
Yip, it is meters.. the lighting isn’t an issue. I’ve had two previous grows in this tent without any issues with that. Only difference this time is the strain.
FirstCavApache64
Well-Known Member
Something to consider is that different strains can have very different light sensitivity and needs, I've run the same lights for three years straight and what made some happy was way too much for others.
oh absolutely, not disagreeing at all. I just tend to think it could be a cal/mag deficiency issue.. maybe with them being in the pot at 5.6-5.7 they aren’t in the range for it.. I believe they just grab at 5.8 and above right?
FirstCavApache64
Well-Known Member
There seems to be a lockout or lack of Magnesium to me with the interveinal chlorosis that's showing. Adding a little Epsom salt would be a good thing to try. I use 1 gram per gallon in soil as I was constantly having issues that looked similar to yours. Coco is not my area as far as nutrition goes, I'm a soil grower. I'm not sure if you're familiar with the Coco for Cannabis site but there's a ton of info and folks that really understand how to grow in Coco.
SofaKingHigh_
Well-Known Member
That is magnesium deficiency or lock out. What’s your run off EC at ?
I'm with @FirstCavApache64 you need some Magnesium. A lot of people use Epsom Salts (I don't so just search for dosing) or buy your nutrient line's additive. For example I use General Hydroponics as my base and so I use CaliMagic which is their Calcium/Magnesium product.
GreenhouseGreen
Well-Known Member
I have three questions.
During your previous grows were you using the same nutes and medium?
You mentioned you started running a lower EC, is there a reason for that?
Once you actually measured the EC of your recipe of 1ml/L of nutes + Si was, what was it?
If I'm understanding your timeline correctly you were doing fine, started running a lower EC, changed strains, and ran into issues. Many of us are running a few or even several strains at the same time with all conditions equal. So, while that can play into the problem, I wouldn't strictly blame that. If my understanding is correct, I would go back to doing what worked if I was you.
calvin.m16
Well-Known Member
Looks like a little heat stress (taco curling on edges of leaves) and definitely magnesium deficiency (yellow interveinal blotching on leaves)
1.2 EC can be too weak of a feed especially when feeding say once a day or every other day. I would increase your base nutrients until you hit at least a 1.6 EC and see how they respond, your input feed pH should be around 5.8-6.0 with that fertilizer. pH is going to usually drop in coco between fertigations which is why I've switched back to ProMix HPCC with the added dolomite lime for pH stability. Also I'm able to mix & feed every other day instead of every day with coco.
With strong lighting, co2, dialed environment I am running sometimes as high as 2.2 EC of MaxiBloom without any sign of burn.
Hopefully you get it sorted.
1.2 EC can be too weak of a feed especially when feeding say once a day or every other day. I would increase your base nutrients until you hit at least a 1.6 EC and see how they respond, your input feed pH should be around 5.8-6.0 with that fertilizer. pH is going to usually drop in coco between fertigations which is why I've switched back to ProMix HPCC with the added dolomite lime for pH stability. Also I'm able to mix & feed every other day instead of every day with coco.
With strong lighting, co2, dialed environment I am running sometimes as high as 2.2 EC of MaxiBloom without any sign of burn.
Hopefully you get it sorted.
Hey mate,
Yeah I was running canna coco last time.. I was running the same nutes but I have added a few others in there from the same range too? The wilt guard and the bio balancer plus silica. The EC with it all together once PH’ed to 5.8/9 was 2.0 with the blue lab guardian. Ppm was pretty high but I can’t remember, I know that softest brands show different ppm. This is a 370usd unit. Things ran pretty bloody smoothly last time yeah.. Do think I should just feed them at full strength as per their recommendations 1ml/l? Maybe pull the bio balancer and wilt guard out and also the silica? I have a cal/mag in there now too.. just want to reset and get it settled. Worst time for it to be happening now I’m in my first week of flower too now.
Thanks heaps, I’ll just run as per their recommendations and hope things pull through. You could be right, it could be just too weak for them. I thought it was a lock out from ph in the soil but I have that all perfect now sitting at 5.8-5.9 so it must be just too low of an EC. Would having too much run off cause a deficiency?
GreenhouseGreen
Well-Known Member
I would run the nutes according to their recommendations and back off if there's issues. 2.0EC isn't crazy but, there's a lot of factors for your desired EC. I give freshly rooted clones 2.1EC without any problems. Every situation is different. It sounds like you were giving a little less than 2.0 considering you weren't adding the newer additives. So, I would run it as it's recommended to be ran and go from there.
As for the ppms, you need to make sure that you're using the right scale. I think the Guardian has PPMx500 and PPMx700. I don't have one. I have a regular Bluelab Combo Meter. I'm pretty sure most charts and people in general go by the x500 scale. In your post earlier you mentioned 1.2/850ppm. That's the x700 scale. On the x500 scale that's only 600ppm. You may have known that but, it's also possible that the fact that there's two scales led you to use less than you need. Also, you can easily math out the relationship between these scales. You simply multiply the EC by 500 or 700.
This is one of the reasons EC(mS/cm) is commonly used when discussing nutes.
This is potentially the most helpful information.. I did know there was a difference but this could mean I’ve very well been under feeding by looking at the wrong scale than what my unit is.. mine also has TDS.. so is that the 500 scale? Then the ppm is the 700? I won’t be taking too much notice of that then just the EC!
thanks heaps!!
GreenhouseGreen
Well-Known Member
TDS is Total Disolved Solids. It is probably the x500 scale. Quick math will easily verify that. The probe measures conductivity and the meter caluates it to what unit you want. On mine there's EC(mS/cm), CF(ECx10), PPM500, PPM700.
EC is easy but some nutrient companies will give you a target ppm. You just have to make sure you know which scale they're using. It also has the benefit of being slightly more precise on these meters. I don't know why they don't take the EC reading out to the hundreds decimal but you can dial in to a greater detail using ppm. I've found it isn't worth it. .1EC is 50ppm on the 500 scale. That's such a small window, I don't really care.
Good luck on your grow.
Last edited:
Mumbeltypeg
Well-Known Member
just checking here.. when you say you are mixing your nutes.. your not actually mixing the undiluted chemicals are you? You should be adding them one at a time to your res.. and then ph correcting, this could be causing issues with your Chem balance.