im going to second weed hounds first post good soil number one stop the britta and there is no reason to ph down tap unless its over 7.5 i let mine sit out for a day or two to evape some chloros man other than that

its not nute burn 40 days in a cup any nutes are probly long gone i flower in cups and have to nute every 6 days.

and to back up my theory the light green is from n def.and the leaves are curling in like theyre praying youll give them some sort of Mg. and ther are other syptoms of def. but im tired of typing not to mention u dont seem like the type to take advice anyway