I have grown some pritty dense nugs with clf's i think it is dependent on strain and how many cfls, last time i had 330 total watts, 80watt 4ft shop light, the rest cfl's
next time im useing 8 30watt cfl, and 8 23watt cfl's and a 50 and a 70watt hps for side lighting in a wood box 2' by 2' by 5'