I've got the light set about 6" above the top of the clones. As for their size, that's more of a screw up on my part. I'm still pretty much an amateur, so much so, this is my first experience doing the mother-clone process. When I cut and rooted these, I was under the mistaken opinion that once they hit flower cycle they stop growing vertically and just budded out, so to stretch out my 'bang for the buck', after they had rooted and been transplanted into the soil, I kept them in veg for about a month until they got the size I wanted. (Or the size I thought I wanted anyways, lol). Thanks to Catbuds for straightening me out on that.