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What is the difference between UVA and UVB rays? Do flourescent lights provide them?
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two oregon newts
one male eastern box turtle
ten gallon tropical fish tank

>>What is the difference between UVA and UVB rays? Do flourescent lights provide them?

UVA and UVB are the names given to two categories of wavelength ranges, UVB (290- 320 nm) and UVA (320 - 400 nm). In terms or reptile keeping they are both important but the UVB plays a critical role in the synthesis of vitamin D3 in the skin which in turn allows for effective absorbtion of calcium from the diet.This pathway is far more important for diurnal basking reptiles then it is for nocturnal and crepuscular species. UVA which is invisible to the human eye but likely visible to most reptiles and birds is thought to play a role in feeding and mating behaviour. Reptiles likely get a more accurate visual picture of both food and potential mates when the full spectrum of UV is provided.
All fluorescents produce UV *but* only those ones specially designed for the purpose of providing it actually produce it in the proper wavelength ranges and emit it. The reptile bulbs have a particular phosphor mix in the tube that produces the UVA and UVB range with a quartz outer sleeve that allows the UV to penetrate through. Regular fluorescents and mercury vapours made for household use are designed to block UV emission.