-snip- i dunno too much about the technical side of lumens or 4-5k, 10k etc... what i can tell you is that you should look into alternating lights. if you've seen any of the heath robinson style setups with multiple lights hanging next to (not above) the plants, people do some amazing things have one set of lights stay on the full 12 hours, and having 1 extra set of lights that comes on for the first 6 of those twelve hours on one side of the plant, and another set of lights hanging directly opposite that the other side of the plant that come on for the last 6 of 12 hours. helps to stimulate auxins like a mofo and ive been wanting to experiment with a single plant cfl setup in my fireplace.