Posted: Tue Mar 20, 2007 11:03 pm
faithin, having two lights is the norm. One for UVB (the UVB lights also provide UVA) and one for heat. Since the UVB lights are flourescent, they are cool. One the other hand, an incandescent (hot) bulb can't provide UVB. That's why you have to have the two.
If you have a very large tank, 55 gallons or up, you can use a mercury vapor bulb (MVB), which truly is an all-in-one. With an MVB you only have to have one bulb, but the MVBs are pretty pricy and you have to have a good ceramic fixture for them since they get so hot.
SpotsMama