Not bad for a first harvest

Brides Cake auto, Day 14. Room temp 81f day/75f night, humidity 37-45%(and struggling to even maintain that), pH has been 6.0-6.4/run off 5.8-6.2, fox farm line at 70%. Six plants total this is the only one with this issue. What I've done: Raised lights; all plants were preying by that evening, so I put back where it was. Moved plant further from fan, which barely blowing to begin with. Maybe wall deflection adding to that one. Coco/perilite wetness is minimal, after water/feed the medium by next day halfway down shows dry on saturation meter. Any thoughts? @Mr. Grow It these new Brides cake are a touchy, slow growing pain in a$$. I'm putting a pic to show this aggravating plant, and pic of a gorilla glue and blue dream the same age and look at the difference.

I have ordered a 10x5 tent I was wondering how many grow lights or what kind of grow lights would be ideal for this grow.? Also how many plants would I be able to fit with a dwc set up.?