As they grow your going to need more lights. I have 3 plants between 12-18" and i use 1 "300W" 2700k cfl, 1 15w tube fluro at 6500k and 1 "150W" 6500K cfl during veg. the 300W being the main light then the two 6500k be supplemental with the tube fluro being vertical. I think i would really benefit from each plant having its own 300W and tube fluro, but at the moment I can't afford that nor have the room. So i'm just saying you will most likely need more lights.