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Bud man 43

Well-Known Member
I have noticed what looks like the beginning of a potassium deficiency-
Possibly calcium deficiency?
Opinions please
Thanks IMG_0160.jpegIMG_0161.jpeg
 
I have noticed what looks like the beginning of a potassium deficiency-
Possibly calcium deficiency?
Opinions please
Thanks View attachment 5349634View attachment 5349635
I have same issue in some places but much further advanced, whole tip turns copper color, dries, and dies but it's not everywhere just older ones and plenty new growth without. It was more of an issue when plants wanted more light come to find out in my case anyway. I am interested what others have to say. Maybe it will help me.
 

Bud man 43

Well-Known Member
Dry medium/pH swings burn the margins of the leaves like that.

Calcium def = irregular rust dots on multiple fan leaves.

Potassium def = lower edges of leaves yellow then burn
Ph is checked each feeding at 6.0
2 gallon fabric pots with coco perlite 70/30 topped with play sand
Currently feeding 2x daily 12 hours apart to runoff
Plants are not too big but are getting to that stage when growth is quick
These are all clones this run and I plan on flowering soon- I have a habit of letting them get too big in veg- then huge after stretch
I usually use 3 gallon pots but I had some leftover 2 gallon and I wanted to use them- again I plan on flipping them when not too big
 

GenericEnigma

Well-Known Member
I have noticed what looks like the beginning of a potassium deficiency-
Possibly calcium deficiency?
Opinions please
Thanks View attachment 5349634View attachment 5349635
Leaf is very dark green. I would consider lockout by nitrogen as a cause (common for what appears to be K and/or Ca deficiency).

Too much Mg can do that to a leaf as well (Mg and Ca each stimulate the need for more of the other).

edit: N does not lock out Ca (thanks, @Billy the Mountain).
 
Last edited:

conor c

Well-Known Member
Leaf is very dark green. I would consider lockout by nitrogen as a cause (common for what appears to be K and/or Ca deficiency).

Too much Mg can do that to a leaf as well (Mg and Ca each stimulate the need for more of the other).
Yeah looks like this i think too much n is locking out magnesium and calcium op whats your temps like lights on /off? Cos temps too low can cause/make nute lockout worse as well anything below 15c locks some stuff out
 

Bud man 43

Well-Known Member
Yeah looks like this i think too much n is locking out magnesium and calcium op whats your temps like lights on /off? Cos temps too low can cause/make nute lockout worse as well anything below 15c locks some stuff out
Temps are around 72 off 78 on currently on18/6
 

Nutty sKunK

Well-Known Member
Ph is checked each feeding at 6.0
2 gallon fabric pots with coco perlite 70/30 topped with play sand
Currently feeding 2x daily 12 hours apart to runoff
Plants are not too big but are getting to that stage when growth is quick
These are all clones this run and I plan on flowering soon- I have a habit of letting them get too big in veg- then huge after stretch
I usually use 3 gallon pots but I had some leftover 2 gallon and I wanted to use them- again I plan on flipping them when not too big
A gallon less media, same watering, is it enough?

I’m still saying pH shifts. Reason being I drought stressed a plant on purpose (and not on purpose) and these burnt rusty margins appeared on a few leaves (not all)

A deficiency will be on multiple leaves as well. Are more leaves like this or just the odd random marking?
 

Bud man 43

Well-Known Member
A gallon less media, same watering, is it enough?

I’m still saying pH shifts. Reason being I drought stressed a plant on purpose (and not on purpose) and these burnt rusty margins appeared on a few leaves (not all)

A deficiency will be on multiple leaves as well. Are more leaves like this or just the odd random marking?
Just a few random leaves- same watering schedule as the 3 gallon pots but still saturated everything to run off and they are still small- i will post pics of the plants
 

weedstoner420

Well-Known Member
Are you sure it's not just physical damage, like from being blown around by a fan and/or scraping against something?
 

Bud man 43

Well-Known Member
You say its not the pH but I'd say the pH is off. Also is that really just coco & perlite? Looks muddy or the sludge from coco.
Topped with play sand- I didn’t have fungus gnats- but to prevent them
Also they are not sitting in runoff- they are on milk crates or small pedestals
 

higher self

Well-Known Member
Topped with play sand- I didn’t have fungus gnats- but to prevent them
Yeah my bad I just reread & pick that up. If you want to be preventive check out Microbe Lift Mosquito Control & you can water it in. Few drops per gallon it will last a long time.
 

DinGrogu

Well-Known Member
Doesn't look like potassium or calcium deficiency. My guess would be the soil. It looks really heavy and not evenly watered. Where did you get the soil? Does it have enough aeration? It could also have hot spots that would cause only certain leaves to be affected but the whole plant looks a little unhappy.

And as far as the lockout thing. Nitrogen can lock out calcium but I don't think it's too much nitrogen.

Nitrogen. When in the form of ammonium, NH4+, nitrogen interacts negatively with the plant's uptake of calcium, magnesium and potassium, particularly when the NO3- (nitrate)/NH4+ (ammonium) ratio is low. As a result, excess NH4+ can lead to a deficiency in any of these three elements.
 

Bud man 43

Well-Known Member
Doesn't look like potassium or calcium deficiency. My guess would be the soil. It looks really heavy and not evenly watered. Where did you get the soil? Does it have enough aeration? It could also have hot spots that would cause only certain leaves to be affected but the whole plant looks a little unhappy.

And as far as the lockout thing. Nitrogen can lock out calcium but I don't think it's too much nitrogen.

Nitrogen. When in the form of ammonium, NH4+, nitrogen interacts negatively with the plant's uptake of calcium, magnesium and potassium, particularly when the NO3- (nitrate)/NH4+ (ammonium) ratio is low. As a result, excess NH4+ can lead to a deficiency in any of these three elements.
It is coco/ perlite 70/30 with play sand topping-
And i do use bti occasionally- it just seems that the gnats show up inside as soon as it gets cold here. I don’t have a gnat problem- just a preventative measure
 
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