OneDude

Looking good ^^ if you want to avoid the one side becoming taller try rotating the plant to give diverse slighting. Essentially the Auxins(hormone) on the darker side of the plant are promoting faster cell division so that the plant reaches towards the light. :sunglasses:

@OneDude, Thanks for the idea. But it seems it all started around week 3, not only on the main part, but on most of the leaves, even the ones hidden from direct light.

@AxlWeed, You should think this: sun's "full power" hours in an avarage spring, summer or autumn day of the year; leaves are like rubber tyres, you can use them in an efficient way up to X miles/km; the structure of the whole plant is very short, compact because of the generous amount of light you give her; every problem in a plant will become worst if anything of the environment is off (temp, rh, nutes, etc.) EDIT: also low rh and "wind" burn (fun too powerful/close to leaves) will end up in a short compact plant with some burns

Cob For life :) Just a mutual trouble: if you have a main cola, that part will receive exponentially more light than the rest of the plant. Those orangish yellowish brownish stripes on the sugar leaves is in fact light burn. Solutions: training the plant into a concave shape (negative of the light intensity) to make it even. grow 2 or more plants so each of it have half cola only under the light and turning them periodically will make every leaf work behind the burning point.