Not a problem mate. One of the things I noticed from my first attempt in the little dr40 is that when it gets bushy on top the light can't penetrate down very far.
My solution was to mount a couple of 2ft T5HO's verticaly in opposite corners of the tent so that there is a decent amount of light all the way down. In the long run I plan to get a couple more so that there is one mounted in each corner.
One the benefits of the small tent, I think anyway, is that you get better light reflection off the walls as they're quite close in.