looks like your PH is off, due to the twisting leaves...which is causing a lockout of some kind. most common is calcium or magnesium...but it is also looking like zinc, and yellowing from the tip inward could be a few things...i want to say it is an immobile nutrient lockout, which one though man is kinda hard for me to pinpoint...i believe the nutrient locked out is immobile, which narrows it down slightly to like 5 different deficiency's. i would flush with PHd water, and hit her with some cal mag plus...plus has chelated iron in it, so it would knock out 3 of the possible culprits.