Which deficiency is it?

[xxorezxx]

Hello guys! A friend of mine got a 4 meters tall girl, which is showing some deficiency on the upper leaves.
He water with plain water with ph on 7.3, the plant is directly on the earth (no pot) I don't have any more info from him, so I just need a simple diagnose please!
Thanks to everyone!

 

[Tim1987]

Hello guys! A friend of mine got a 4 meters tall girl, which is showing some deficiency on the upper leaves.
He water with plain water with ph on 7.3, the plant is directly on the earth (no pot) I don't have any more info from him, so I just need a simple diagnose please!
Thanks to everyone!
View attachment 4103077

Thats classic MAGNESIUM!!!
You need to know, if you have deficiency or toxicity. Before you give magnesium or take some away.
PH?
EC/PPM?
Good luck
Tim

 

[grassy007]

It's actually Potassium deficiency according to the pics at this site. The leaves there look very similar to yours.

http://www.ilovegrowingmarijuana.com/guides/marijuana-plant-care/marijuana-nutrients/

 

[Tim1987]

Thats classic MAGNESIUM!!!
You need to know, if you have deficiency or toxicity. Before you give magnesium or take some away.
PH?
EC/PPM?
Good luck
Tim

You have "the magnesium V".
It'll work from the bottom up.
Ph?
Ec/ppm?
Good luck.
Tim