My plant has a little browning around the edge of one of my leaves. It is a white widow. My light is a few inches away from the plant, and I am using a reflective blanket purchased from wal-mart.
Help me understand what you are thinking, you know there are all kinds of lights out there right? Some will cook your leaves in a second if you got them within a few inches, why wouldn't you tell us about your light?
My light is one of the yellow industrial lights, 13W. It is a fluorescent light, but pretty bright. Is that the problem? Because, it seems like it has been grwoing quite healthfully, and growing at a fast rate.
I have normal potting soil mixed with a little vermiculite and perlite. The problem way be not enough water. Since I put the relfective blanket on, the soil has been drying out quicker, and I may need to be more diligent with watering.