Weird Leaf Problem

Puede que te hayas pasado regando, pero sigo pensando que tienes de defoliar esas hojas grandes y con boquetes, las primeras hojas de abajo que ya son muy viejas y las que dan sombra a los brotes :S no tengas miedo a podar, estas plantas son muy fuertes y lo agradecen ;)

Possible the light is too intense so close also, this could be contributing to the damage done to leaf.

If the grow areas is too hot (above 86 °F/30 °C), or too cold (under 55 °F/12.78 °C) the plant is unable to transpire and move water throughout the plant. This also causes a wicking of moisture from the plant tissue and will cause the leaves to shrivel, twist, or curl up. You should know yourself how accurate your temps are. If your sure its not that then move to nutrients. Nutrient deficiencies Nitrogen: A lack of nitrogen can cause leaves to curl up. Phosphorus: A lack of phosphorus can cause older leaves to curl, distort, and remain smaller than normal. Boron: A lack of boron can cause leaves to curl up. Boron also cause dwarfism as is responsible for cell elongation. Not nitrogen, would be visible. Not likely phosphorus I'd expect other symptoms.

Hey growmie, I think its just a bit too crowded down there they have little to no space to spread out, I suggest removing one or two biggest leaves that take up the most space and don't let air and light penetrate your canopy, then the smaller ones might get some space, good luck!