I use daylight cfls to get to the bottom of the enclosure. The lighting isn't full spectrum, but bright and natural looking to human eyes. You can get 100 watt equivalents fairly cheap, they are actually only 26 watts but supposedly bright as 100 watt incandescents and the light gets down to the bottom. In bigger cages 150 and 300 watt equivalents are available at lowes, and these are very bright with lots of penetrating power and still not a lot of real wattage for the light.