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Help assess my plant’s issues!

  • Thread starter Thread starter GreendangerMN
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Help assess my plant’s issues!

GreendangerMN 51 Replies 3,620 Views
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GreendangerMN

GreendangerMN

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#1
Hoping someone can help me diagnose what is happening to my plant. Grown in 70% coco 30% perlite (Tupur) and fed Cronk Nutrients full line. Ph has been consistently 5.9 and EC at 1.5-1.7. Any advice would be greatly appreciated! Thank you!
 

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#2
Looks like a deficiency triggered by low pH to me, now beginning to struggle getting calcium. Below 6.0 the plant can't eat calcium, magnesium, and a couple other things it has marginal uptake in pH lower than 6. I've included a chart to show the sweet pH range for cannabis.
 

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#3
Ninjadogma said:
Looks like a deficiency triggered by low pH to me, now beginning to struggle getting calcium. Below 6.0 the plant can't eat calcium, magnesium, and a couple other things it has marginal uptake in pH lower than 6. I've included a chart to show the sweet pH range for cannabis.
Click to expand...
Thank you! Does this chart still apply the same to coco as opposed to soil?
 
#4
Ninjadogma said:
Looks like a deficiency triggered by low pH to me, now beginning to struggle getting calcium. Below 6.0 the plant can't eat calcium, magnesium, and a couple other things it has marginal uptake in pH lower than 6. I've included a chart to show the sweet pH range for cannabis.
Click to expand...
GreendangerMN said:
Hoping someone can help me diagnose what is happening to my plant. Grown in 70% coco 30% perlite (Tupur) and fed Cronk Nutrients full line. Ph has been consistently 5.9 and EC at 1.5-1.7. Any advice would be greatly appreciated! Thank you!
Click to expand...
5.9 ph is fine in coco. That shouldn’t be your issue. I feed lower ph than 5.9 in coco all the time and see no issues. Where mine lands between 5.5 and 6.3 I send it and have never ran into a problem

Sometimes young plants can be hard in coco because you have to start introducing nutes so early. A lot of times when they are small like that I get some weird colors and they grow out of it. Idk this line of nutes but does it have cal mag of any sort?
 
#5
Also make sure your ph isn’t drifting. Are you phing the water before the nutes are mixed in? Check after you mix as well just to make sure nothing in the nutes is making the ph change.
 
#7
Here's a chart that applies to coco. Coco is considered a hydroponic medium.

Nutrient uptake chart hydro
 
#8
What strenght are you feeding? Since when and how often? Looks like a 5-7 gal pot (cant see if its tubular or not), I wouldnt have started feeding so soon. The only affected leaves are the new ones so far.
 
#9
The first set of true leaves is still perfectly green which is an indicative that they still have plenty of food in the soil.
 

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#10
Oh man I just saw your EC, thats bad, thats more than triple what it should be getting. Is that the EC of your water with nutes or in the soil? In whichever case is bad. You dont want more than 0,5-0,8 EC when theyre still so young, as they grow you can increase to 1,5 and flor flower you can go up to 2 if they can take it well, you gotta read them to know when youre giving too little or too much.
 
#11
Eledin said:
Oh man I just saw your EC, thats bad, thats more than triple what they should be getting. Is that the EC of your water with nutes or in the soil? In whichever case is bad.
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FYI - OP is in coco, not soil although I do agree that his EC is high enough to fry the plants ... if indeed the reading is correct.
 
#12
RoadKillSkunkHunt said:
FYI - OP is in coco, not soil although I do agree that his EC is high enough to fry the plants ... if indeed the reading is correct.
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Yes I know, still too high like you said. If that was the EC in an organic soil I wouldnt be worried but being coco is way too high at that stage.
 
#13
I guess this is debatable but here is a chart. That plant is in between seedling and early veg, not quite early veg being so small, I wouldnt consider it early veg at least. Maybe if the pot was small then I would go closer to early veg EC but pretty sure that coco was buffered. And if its not then well... thats not good either.
General EC Ranges for Cannabis in Coco
SeedlingEarly VegLate Veg
400* – 5001100 – 14001200 – 1500
 
#15
More than burnt it looks like it has a lock out problem because when the veins remain green its usually that the leaves are not recieving a key nutrient. Are you using tap water? And the calmag from that line? (Im assuming youre using the calmag since you said your using the full line). Coco holds on to calcium a lot but if you over do it youre still gonna cause problems, it can only hold so much, and after that excesses can be very problematic
From google so I dont have to type:
Too much calcium in coco coir can cause nutrient imbalances, specifically leading to deficiencies in magnesium and potassium. This can result in stunted growth, leaf discoloration (browning or yellowing), and reduced overall plant health. While calcium is essential for plant growth, excessive amounts can hinder the uptake of other vital nutrients, disrupting the delicate balance needed for optimal development.
 
#16
If I had to guess Id say thats magnessium deficiency. I dont see burnt tips on the leaves and with such high EC is rare so Im pretty sure its a lockout in general of nutrients but specially magnessium.
 
#17
Eledin said:
If I had to guess Id say thats magnessium deficiency. I dont see burnt tips on the leaves and with such high EC is rare so Im pretty sure is a lockout.
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I'd be more inclined to call it magnesium lock-out. I bet there's plenty in the soil but its uptake is being prohibited by all the calcium being sucked up by the coco.
 
#18
Yes, deficiency due to lockout, he clearly is putting a lot of magnessium in the coco 🤣 so its there.
I would flush and work my way down to the minium EC showed in the table for early veg. Your roots have yet to colonize all the coco and if its buffered there's no reason to start feeding unless your true leaves start losing color.
 
#19
Oh shit and before I forget, keep in mind that if you flush you will probably have to buffer some extra calcium that will just bind with the coco and stay there. If youre using tap water then no worries but if youre using RO perhaps put some extra calmag after the flush only once and keep the other things lower then keep using calmag as usual without surpasing the showed EC with the overall dosages.
 
#20
Eledin said:
Oh shit and before I forget, keep in mind that if you flush you will probably have to buffer some extra calcium that will just bind with the coco and stay there. If youre using tap water then no worries but if youre using RO perhaps put some extra calmag after the flush only once and keep the other things lower then keep using calmag as usual without surpasing the showed EC with the overall dosages.
Click to expand...

Also, alternate epsom salts dissolved into your feed water at a teaspoon per gallon every other watering. Since you're in coco, we'll be looking for the sweet spot between just enough calcium to supply the plant's needs without over-doing it. The epsom salts provides magnesium which you will need as you move through this issue.

Anyway, keep following along with @Eledin. He's covering the bases quite well. I've only been stepping in for clarity when I think something needs a bit more explanation. He's spot on with his observations.
 
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