we have the similar problem with dying/yellow leafs !
my plants are in flowering for 2 weeks but i kept them in veg for i month ! Some leafs (most the bottom leafs ) turn yellow and just fall off . Temperature and humidity is right, runoff ph also !
Try to put your problem in PLANT PROBLEM section , maybe someone can help you.

I tried but no results ! If you figured out something, please let me now ! :thumbsup:

Peace !