Thats exactly what it appears to be. Add a 1/4 teaspoon of epsom salt per gallon to ur waterings and see how that does. If thats it, u will see a difference after about a week or two. The purple will lighten upive heard red stems means mag deficiency. what are you feeding them again? I can't remember...
dude, that pic of the leaves looks hungry. as i suggested, check your ph from runoff, because i am sure that it's low and causing some nutrients to lock out.Its been in flowering for 3 days, those little leaves just grew out & its a zoomed in picture so they look droopy.
Ill try the epson salt thanks for the info.