I grabbed enough free samples from advanced nutes to do my small tent crop, Im all about the "free" part in free samples. Im running 4 x g13s, three in the 50/50 promix/perlite mix and one in coco. Feeding everything the AN food except one, that one i kept on the blue powder..until she got 3 inches behind..Now she is on AN.. I dunno what to tell you bro. Also plants in our perlite/promix combo are out growing the one in coco, not by a lot but by enough..
As for your girl Id flushed her out well with some super low low low ppm plant food. Not enough to feed but just enough to bind with the excess food {salts} that are already locked into the soil and drag them down and out. That way she can eat some of the green out of her leaves. If your big lower fans stay green you know your on the right track feeding water or low ppms, if your lower fans start to yellow or fade its something else. I had similar problems with the 35s and the g13s in veg, i think it has to do with urea but its all to much to type and I know you have the interweb skills too look it up =)
Now i could be totally full of shiat and be 10 miles off about all this...I figure the odds are 50/50 amigo.
Peace, Te Lilman