Flourecent Lights Compact Vs, Tubes??

I have a fixture that has two 4 ft cool white flourecent tubes in it, I believe each one is 40 watts so thats 80 watts total. I have a third smaller 2 foot tube in there for an additional 20 watts of cool white. So I guess that is 100 watts total. I thought tubes was the way to go as I can easily raise and lower the fixtures heights. However they take up quite a bit of room. Would one 100 watt compact fkourecebnt equal the same light as the three tube I have in there now? At this point I just want to make sure I have enough light to complete the vegging on flourecent only. I think I may need to add some compact flourecents or another 80 watt tube fixture. Your thoughts? I think a 400 watt HPS will handle the later stages. My space is 2DeepX5wideX5high 3-4 plants max