that white-ish colored spot on those leaves is from the light, there hotspots. areas of high intensity that bleach the chlorophyl to a crisp, it leaves blotches light that if left in the same spot over time. i would start rotating plants around and the leaf curl yer getting and the hard ridges on the leaf blades is from to high of intensity, raise the light up as they grow to keep from stunting the new growth. your yeild has already been effected so your yeild will be diminished. the leafs that are drooping on the sides and still remain ridged in the center could be overwatering.
what is your temps in your grow area? do you have good ventilation?
theres things you can do to help get those plants really growing....keep um green!