Problems with leaves, curling, spots

Hello,

These plants have been growing for about 5 weeks now. I have the lights 18 on 6 off. The tallest one is 19" or so. I was (what I thought) having problems with not enough water early on, because the lower leaves were turning yellow and dying. More water seemed to fix this. However, now I've noticed some spots on my leaves and they are starting to curl under. I have noticed little gnats or something flying around. I kill a few a day or so. I have a fly strip up in there now. By looking at these pictures, can anyone tell me what's going on here??

I've also thrown in a few other pix of my girls (fingers crossed) lol.

Many thanks,
Durameter