Just opinion, I like the reuse of containers, Nicely done. So here's what I gather; CFLs, ambient RH, CO2, and temp, initially watered w/ ph 8 water, not domed, and no foliar feeding, leaves yellowing, drooping and edges are browning. Since you have a few, maybe you could run some tests. Dome a few during lights on and see if that helps. More humidity can help. If you're running 24 hours lights, maybe lightly foliar spray some w/ proper ph 6.5 water or seltzer. I usually snip any brown parts of leaves when they are young, but it does slow the growth. Be careful not to take too much of the yellow parts, sometimes those parts can turn back to green, when you get the situation corrected. The only time I've had seltzer water hurt my plants was when I had over watered. Try getting some extra CO2 to some of your plants to see what that does. If these remedies sound stupid, its just opinion.