(Not A Noob) Lime green leafs/No yellowing (HD Pics)

i think your PH is off causing a immobile nutrient lock-out...whether it be zinc, iron, or any other immobile nutrient that the plant needs. Magnesium is a mobile nutrient, meaning that it will start at the bottom, and work its way up, or even start in the middle...another thing i noticed was the slight twisting, and contorting of the leaves. not always true, but in most cases it's cause by PH issues, which doesnt necessarily mean prurely ACIDIC, or ALKALINE...it also includes fluctuating. adding nutrients will bring your the PH of your water down, so if you've been feeding and then watering without testing that;s a problem...not saying you are, just stoned and brainstorming...hope it helped?!

Looks like the beginning of an Iron defenciency. This may help you.

https://www.rollitup.org/attachments/marijuana-plant-problems/1894318d1317184266-guide-nutrient-deficiency-toxicity-deficiency.jpg

http://www.greenmanspage.com/guides/plant_abuse.html

Don't sweat it give your plants some cal mag plus and it will have all the iron, calcium and magnesium you need.

here is a ph chart...