I agree with sso just lst it..... tie it down a bit and whenever it tries to grow up more add another string.
I myself have a cfl cab for motherly purposes as well (2) 6500k + (1) 5500k 26w each = 300watts. I get about 5200 lumens in it (2w x 3 1/2h x 13"d cab). What I decided to do to get even growth was scrog. Just build yourself a little frame and make a checkerboard out of string with it. I dont even have my plant tied to the screen im justr making sure it stays below it. The string should offer enough flex to prevent the plant growing into it (that tree down the street with a fence pole in it) also it will make re-moving it from the enclosure much easier (scissors
)
Good luck with the grow, I hope all goes well