You need something like this:
Amazon.com: Prime CL050506 Reflector Clamp Lamp with 6-Feet 18/2 SPT-2 Cord, 8.5-Inch: Home Improvement
2 cfl lamps eqivilent to 120 wats each at home depot for less then 15 dollars.
I got the clamp on at home depot.. 5.99 then the 23 watt cfl 5100k bulb at home depot 8.99 works great for the macro in the tank.