i use 8 23watt 2700k for flowering, and 6400k for Veg ( i ran 24/7 for ~4-5 weeks, also did 1 week of transition 18/6 before 12/12) from everything i have read the more lights the more lumen = more penetration. Even tho lumen arent a huge factor in cfl growing. i like to keep my plant around 83degreese. all my lights about 2-3" away. Used fishing string after nugs started to develop to pull down the smaller nodes under fan leaves to get better light. Seemed to be working great. i didnt let a lot of nodes grow so the lower part is bare and the kola is full, its about 8-10" long atm still going. total plant 18" tall