WTF is this?

[NugDragon]

I am growing 3 Jack Herer autos, and 1 phenotype grew out twice as tall as the others and is unfortunately only a few inches from my 600w LED because I can't raise my grow light any higher in my 180cm tall tent. I am in week #12, and everything has been fine concerning the distance from my light, as it has stopped growing in height for the last few weeks and has generally been around the same distance. However, just tonight I looked inside to check, and only a few of the leaves on the top of the main cola started to turn orange on the outer points of the leaves (left and right, not just the end of the leaf), and there are these orange-like spots over them that basically look like random tea stains. I was thinking initially that there was some sort of nute deficiency going on, or maybe some sort of odd pest...but it's ONLY on the top few leaves on the main cola and on 1 plant. Is this light burn, or what? The outer tips aren't significantly curling and there is no taco-ing. Does anybody have any idea what this could be and how to take care of it?

 

[charsi420]

Super crop the tall one.

 

[Sobeit]

Possible excess iron, or rust.

 

[NugDragon]

Super crop the tall one.

Ok, what does it have to do with the odd coloring on the leaves, though? Do you know what it is?

 

[charsi420]

Looks like light burn.

 

[Roger A. Shrubber]

probably light burn, hard to tell from the pics. you're overfeeding a little, at least too much N, see if you can find something like 5-11-26 for flower. i was using 12-15-30 and it was too much N, was giving me foxtails