If you set up any new tanks in the future you might want to consider
your plant selection for the tank for floating plants, that way you can
use the weakest available light (probably will be standard fluorescent
admittedly) and the floating plants will grow good if that previously
mentioned light is close enough (hence the recommendation of floating
plants to keep them close to the light). Coincidentally that turned out
to be what I do plus obvious use of low light plants on my part (such
as crypts and anubias which is too early to tell if they are growing
yet). Also - floating plants tend to grow faster than rooted plants.
Conservatively speaking you probably should double the light wattage in
general for your tank you speak of just for your benefit before you get
hooked to the idea that they're supposedly just plants that should grow
under any conditions which is my common failed thinking. Good luck and
later!