okay so basically i wanted to set up another light for my planted tank. i went down to home depot and bought one of those pre assembled 2 foot double lamp flourescent fixtures that are made to hang from the ceiling. i wanted mine to rest on the top of the tank though. so all i did was cut a couple of pieces of plywood the length of the fixture and slightly taller so that the fixture would rest on the plywood instead of the flourescent tubes.then i got a few sheet metal screws drilled 4 holes and fastened the wood to each side of the fixture. this also helped direct the light down into the tank better. the only other thing i did was paint them white to reflect the light off the sides. the whole project took about a half an hour. it was a cheap set up but one that's not really energy efficient as it uses an electomagnetic ballast and t12 bulbs. if you are after a more high end energy efficient diy set up you could probably buy one of those retro fit kits that will run t5, or power compact bulbs comes with end caps, reflectors, and an electronic ballast and just build your own canopy,but you'll pay for it. the cheapy set up i put together only cost me around $45, i already had the paint and plywood laying around the house so all i really paid for was the fixture and a couple bulbs.