I don't know why UV lights would stop producing UV light after time, except that they'll probably burn out in about 6-8 months. Fluorescent bulbs put out a lot of light, but not a lot of heat. Depending upon how cool your room gets at night, you might just choose to use a standard soft white light bulb during the day, and turn it off at night. A 5-10F drop in temp at night is perfectly fine. If the temp drops over 10F, then you might consider a heat pad under the tank or an IR bulb. Again, these are just my preferences. There's certainly more than one right way to raise a snake.
