You should keep the bulbs of the lights in proximity to the very tops of the plants - just far enough away that you can adjust them when they are going to be touching. So within an inch or two if you check on them frequently... and at most keep them within a few inches even if you don't check them too frequently. You'll get more compact growth that way (they do look stretched and you are only going to get a decent amount of buds from the very, very tops as they are now). You could also LST down the highest plants to all be the same height as the shortest ones that are under the same lighting fixture (make an even canopy so they are all equally close to the light). Otherwise, they look healthy.
If you have some hobby time, you could get some panda film or mylar sheets and build a little PVC or wood frame enclosure to contain/reflect some lost light as well.
Okay, I just wanted to get some feedback on these. The first two are just a far away general overview pic. The second is of my purp plant as I am calling it because of the purple stem. Now the fourth I have a question for. It's my buddies plant and he was trying to open up the branches so the middle of the plant can get more light. BUT, he accidently almost ripped it in half. As you can see, we tied strings to it to hold it together and it happened about a week ago, possibly two, and it hasn't died yet, but it seems to be a little more frail than normal. The fifth plant is a random strain that I'm calling Christmas Tree due to it resembling one. The last is mine. I was just curious if you can see how much I would get off of this plant. I know this description is a little vague and I've stated in other posts about the light schedule, ferts, and medium. Should they be closer to the light? I put them on 18/6 (light/darkness) for ferts I use Miracle Gro 24/8/16 which has been working great. I feed them every other watering. I use Miracle-Gro moisture control medium. I try to keep them within a foot of the lights. I don't really check on humidity or temp. I figured if it's warm for me when I walk in, they'll be fine. I also have a heater now that it's nearing time for winter. and I have two fans blowing on either side of the setup.
