You can get like 12feet of insulated LED (blue) at Home depot for less than $10. I did, and installed it around the bottom inside edge of my PC canopy in about 20 minutes.

Piece o' friggin' cake.

The power cord goes down into the cabinet with the rest of the PC cords, and it plugs in separately to a timer that has it turn on when my PCs go off at night.

Now my fish can see the 10 inch fish eating carpet anemone before it's too late!!

(it comes with screws & clips that you can install into the sides of the canopy with a drill, fyi)