that CFL bulb is small... is that the 60W EQ? soft white? bright white? daylight?
you need to cover the side walls, with mylar or wraping paper..
you need some kind of reflectivity, not just from the top, the tops get enough, from the light..
also, you need to upgrade lights, that 1 bulb wont grow, the whole way through
& if you try, you will go through slow growth & your plant will eventually die..