Currently using a 400W sodium light in an outdoor floodlight fixture.
I'm not sure how many watts it actually uses; probably close to 500W
and although the bulb is very efficient the fixture is not. So I'm
thinking about one of these (haven't decided which of the 2 yet):

http://store.yahoo.com/pro-lighting/4lat5flhibay.html

http://www.fullspectrumsolutions.com...res_35_ctg.htm
(the 4-lamp version)

What do you think? The fixture from FullSpectrum has a more efficient
ballast, but the energy payback would take a long time. Also I wonder
if the included 5900K lamps produce enough red spectrum for efficient
use as a grow light. Of course I could pull 1 or 2 of the lamps out
and keep them as spares and replace with 2700K or 3000K tubes.

Bob

LED plant grow lights are very suitable for any type of aquarium. These mounted lighting system has a higher initial cost. However, they have a reputation for more than 10 times lasting compact fluorescent lamps.