You may want to make up a foliar spray diluted with some organic compost tea or make your own brew up.
They look a little dry and stressed and will help if you are suffering from any deficencies. Also if possible steer clear of using aluminum foil for reflective material. How much light are you hitting them with in ur cab for flower? Do you have good venting and air circulation?
You're right on the money. I moved the light up yesterday (about 16" from canopy now). The leaves that were a little scorched feel a lot softer and they're looking a little greener to. For lighting I have a 150W HPS. I guess that's why at first I thought I could get away with having it so close. I was actually 6" from the top when I started. They looked great after 10 days under the CFL . . . didn't take long for the leaves to get singed on the edges and turn yellow. First grow . . . live and learn I guess.
For reflective material I'm using 2mm Mylar. For my flowering cabinet I plan on using that white plastic material (not sure of the proper name).
For air flow I have a passive intake on the bottom of the cabinet. For exhause I am using an inline 100 CFM fan that pulls air via a 9" Carbon Filter. That runs 24/7.
There is also a small clip on fan inside that hits the plant (not head on of course) and that runs on the same timer as the light. I am however going to replace that with an oscillating fan when I find one.
For cooling I took the top vent off the HPS and bungied a fan that blows air directly over the heat shield. That is also on the timer (on when light is on).
I'm in the process of buying a 6' cabinet for flower and use my current one for veg. The HPS will go in the new cabinet and a 175W Metal Halide in the veg one.
I think I'll just buy another 150W HPS for the flower cab. Yeah a 250W would be better. But (2) 150's will spread the light out and of course I really like the fact they cause minimal heat issues, plus I have one already. They're a lot smaller then the 250's and 400's as well. My next grow is going to be (3) plants (all different strains) so I think 300W for flower should be good. I only grow for my own personal use . . . any extra I'll give away to a few trust worthy and close friends.
Gotta hit the hay but I'll post up some more pics tomorrow.
Thank you very much for the feedback.