What UVB lighting should I purchase?

[ZEROPILOT]

This is a general guide that I hope helps someone.
UVB is required for all tortoises not living at least partially outdoors. And buying the correct type of lamp and fixture can be difficult. There is so much out there.
First of all...What NOT TO BUY:
Do not purchase a "CFL" Compact, coiled, looped or spiral florescent bulb. The kind that screw in.
These can cause serious eye issues and don't broadcast UV in wide areas.

 

[ZEROPILOT]

Do not use a Mercury vapor UVA, UVB and heat, "all in one bulb".
They do not last long and do not broadcast UV reliable. And can either offer way too little or way too much UV.
They're also very drying to a tortoises shell.

 

[ZEROPILOT]

DO USE a florescent tube fixture that is a T8 size if your tortoise is no more than 12" away from the light.

Use a T5"HO" fixture if your tortoise is over 12" away from the light.
A T5 is twice as powerful as a T8.
The width of the fixture should be the width of your enclosure. Or use more than one.
If you are placing the light on top of a screen top. The screen will filter out half of the UV. So instead of a 5.0 T8 or T5, use a 10.0.
5.0 is for forest species. 10.0 is for desert species.
A 5.0 or 10.0 are available in both T5 and T8 types.
ARCADIA lights are 6% or 12%. Not 5.0 and 10.0.
Do not mount any UV lamp on top of glass or plexiglass. The UV will not pass through.
The most commonly used UV LIGHT is probably the 24" T8 5.0 florescent.