It may not be my place to step in, but in my experience with tubes, do not let your girls get too tall. flower at about a foot or less. Im using about 195 watts of cfl, and it is not enough for 4 plants. I need more lights as it is. Im really hoping that I get at least 2 males so I can kill em. Flower em early dude.
I had some plants about Reaper's size a few years ago under fluoro tubes when I decided to flower and they ended up to be taller than me. I was real proud of some 6 foot tall plants, but the yield was next to nothing.