u could put the flourescants at the bottom of the plant and the top, but if you don't have the supplies (enough lights) or time to do so you can find a different way. This is what I'm doing. a cheap 150 watt incandascent grow light on top for the leaves and photosynthesis, then a flouro on the bottom 40 watts total that makes sure all bud sites are fine. and u don't really need to worry about light penetration as much as u are in veg, but it is good to think ahead. but I would worry if bottom leaves have no light and die.