Cal-Mag Deficient or What?

D

DIY-grower

New Member
Hello all,

My SAD is showing signs of continuous Cal-Mag deficiency even though I have added more and PH corrected the water. It’s getting frustrating because I am losing more leaves than it can produce. Older leaves are affected first and it yellows out in between the green veins. I have added pictures as well.
 
dbz

dbz

Well-Known Member
I am not an expert at growing Cannabis in any way.
You should probably include more information including your nutrients the basics of the grow.
From what I know of other gardening it looks like to me to be a Magnesium deficiency but you may have some kind of problem with your solution other than that and that's where you need to tell people here how you are growing.

If it is too humid that can hurt Magnesium uptake in plants. Too cold, you can lock it out. Too much Potassium you can lock it out. You could try a Foliar spray of Epsom Salts in the short run, but you probably need to give more information about your exact nutrient regiment, environment and everything else before people can tell you exactly why your plant is locked out of taking up magnesium.
 
D

DIY-grower

New Member
dbz said:
I am not an expert at growing Cannabis in any way.
You should probably include more information including your nutrients the basics of the grow.
From what I know of other gardening it looks like to me to be a Magnesium deficiency but you may have some kind of problem with your solution other than that and that's where you need to tell people here how you are growing.

If it is too humid that can hurt Magnesium uptake in plants. Too cold, you can lock it out. Too much Potassium you can lock it out. You could try a Foliar spray of Epsom Salts in the short run, but you probably need to give more information about your exact nutrient regiment, environment and everything else before people can tell you exactly why your plant is locked out of taking up magnesium.
Click to expand...
I am currently running with a three part nutrient solution at 20 ml each for a 20 ltr bucket. The humidity is a steady 58%, I have upped the PH to 6.2 as research indicates its best for magnesium uptake. The PPM is close to 1000. I am adding Iced bottles of water, sealed and everything into the bucket which brings the temps to 21 Celsius. I have another strain growing next to it which runs the same schedule with ice bottles involved, but it is cruising along perfectly. Do you recommend I flush and restart? Also, I have been following a precise chain of adding the nutrients starting with Cal-Mag and then the three part nutes. I have just tried foliage spray and the plants drooped a little.
 
myke

myke

Well-Known Member
How do the roots look?1000 ppm is kinda high for that small of plant.1ml/l of calmag is normal with tap water,RO youll need more.Some strains just want more.
 
EvilScotsm@n

EvilScotsm@n

Well-Known Member
Divide the base nutes by 4 mate. You want those around 250ppm for a plant that size. Then because you're in ro add on 100ppm of calmag. That strength of calmag will do you for quite a while.

Ph to 5.7 and let it drift up to 6.3-6.5 before you bring it back down. Should take about 5 days to swing up.
Then just follow the ppm.
Once the ppm of the res starts dropping up the base nutes (not calmag!) By 50%.
Once the ppm starts dropping at that strength go up again by 50%.
All there is to it mate. Just follow the number on the ppm stick like a monkey.
If it starts rising then add water with calmag at the same ml/L ratio required to make the 100ppm.
When it starts dropping by more than like 10% per day go up 50% with the base nutes.
:)
 
D

DIY-grower

New Member
EvilScotsm@n said:
Divide the base nutes by 4 mate. You want those around 250ppm for a plant that size. Then because you're in ro add on 100ppm of calmag. That strength of calmag will do you for quite a while.

Ph to 5.7 and let it drift up to 6.3-6.5 before you bring it back down. Should take about 5 days to swing up.
Then just follow the ppm.
Once the ppm of the res starts dropping up the base nutes (not calmag!) By 50%.
Once the ppm starts dropping at that strength go up again by 50%.
All there is to it mate. Just follow the number on the ppm stick like a monkey.
If it starts rising then add water with calmag at the same ml/L ratio required to make the 100ppm.
When it starts dropping by more than like 10% per day go up 50% with the base nutes.
:)
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That sounds like a straightforward plan, thanks a ton man, going into it right away.
 
EvilScotsm@n

EvilScotsm@n

Well-Known Member
I know it all sounds complicated just now mate but honestly, once the penny drops you'll see how easy it all is.
Always best to stick to the lighter side of feeding and to try avoid the ppm rising at all.
If it's rising then all rules about deficits go out the window. The first thing to get locked out are the metals. Magnesium and iron.
Makes it look like the plants are deficient no matter how much you feed.
If you keep it dropping though then you know straight away that your deficit is precisely that. In which case you just up the dose of whatever slightly.
Yours isn't though. Just lockout from over feeding.
It'll take a week for her to look back on track so be patient:)
 
Last edited:
D

DIY-grower

New Member
EvilScotsm@n said:
I know it all sounds complicated just now mate but honestly, once the penny drops you'll see how easy it all is.
Always best to stick to the lighter side of feeding and to try avoid the ppm rising at all.
If it's rising then all rules about deficits go out the window. The first thing to get locked out are the metals. Magnesium and iron.
Makes took like the plants are deficient no matter how much you feed.
If you keep it dropping though then you know straight away that your deficit is precisely that.
Yours isn't though. Just lockout from over feeding.
It'll take a week for her to look back on track so be patient:)
Click to expand...
Now that’s what I wanted to hear. For starters I am going in with the 4 part feed and try to follow your guide from there. Also, I begin loading the bucket with Cal-mag first, followed by the nutes, I hope that works?
 
myke

myke

Well-Known Member
I would run plain ph water for 12 hrs to give it a flush,drain then reload as suggested.
 
EvilScotsm@n

EvilScotsm@n

Well-Known Member
DIY-grower said:
Now that’s what I wanted to hear. For starters I am going in with the 4 part feed and try to follow your guide from there. Also, I begin loading the bucket with Cal-mag first, followed by the nutes, I hope that works?
Click to expand...
Some say add calmag first. I add mine last and can't say its ever caused me grief.
 
D

DIY-grower

New Member
EvilScotsm@n said:
Some say add calmag first. I add mine last and can't say its ever caused me grief.
Click to expand...
Thank you for clarifying that bit as well. The last area to probe is me adding bottles of iced water to reduce the temps. The exposed roots come directly in contact with the bottle, any chances of that playing the fowl?
 
S

spek9

Well-Known Member
EvilScotsm@n said:
Some say add calmag first. I add mine last and can't say its ever caused me grief.
Click to expand...
I'm the exact opposite (my Cal-Mag goes in my stock tanks first), with no problems (ie. no precipitation). By the sounds of it, if for some reason that I forget to add Cal-Mag first, it won't be the end of the world.
 
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