Sorry, I'm not a hydro guy.

Just a guess...but possibly too high ph, and slight overnute...?
What's your nutrient schedule?
Temp swing is marginal. If possible, keep within about 15 degrees f. high/low. The wider the swing, the more it can stress the ladies.
Do you use any other additives, sprays, goops or gels? (micronutes, CalMag Plus, Liquid Light...)

Again, I'm a soil guy, but answering these may help others to help you.

Good luck.

Edit:
I just saw your pix...and nothing looks at all drastic. Matter of fact...they look pretty good so far. :thumbsup: