2 ft tank

I have just set up a 150 gallon tank with a 2 ft depth.  I'm preparing to build the lighting hood and had planned on 8 4 ft fluorescent tubes to light a prospectively densly planted tank.  I would be very interested in the groups opinion of fluorescent tubes for this application.  As I remember from my engineering classed, light intensity decreases as an inverse square of depth.

Scott Corbeil