Here is what i used.
http://www.drsfostersmith.com/Produc...&N=2004+113544
I have not tried the suction cup ones, I did not know they were submersible, way cool. These took about 20 minutes to install. Depending on your light fixture you may have to cut it to fit the lights. It is not the difficult if you got a Dremel tool with a cut off wheel. There are 4 screws holding the fixture to the frame. just take em out and cut the hole in the fixture. Watch out for the wires! They came with screws, Just cut the hole so you have a tight fit and you shouldn't need them. You will also need to cut a hole for the power cord in the Hood frame. You can link up to 3 of the lights off one power cord.
What I like about the Red one is the fish can't see it, they think it is dark so I can watch my Catfish come out to eat after dark. Also my Silver Dollar is alot more active at night than the day. He looks Awesome in the red glow! Here are some pics of what it looks like installed on the light hood. There is a red one and a blue one. Hook em up to a timer with your Fluorescent light and you are one hooked up (lazy) fish keeper!