I have a question about my UVB. I have a long UVB bulb which sets ontop of the enclosure. But I don't have a way of putting it in the middle, so one side is illuminated and one side isn't. Is this still getting my torts UVB?
Yes, a picture would be most helpful. We'd need to see if you're screening out the UV rays by setting the light on a screen, or glass/plastic cover.
I really don't think it matters where in the habitat the light is mounted, as long as there are no restrictions for the light. The rays actually float around a bit, they don't just go directly down to the floor.
As long as the distance from bulb to the ground is what the manufacturer recommends, then yes- the 'pool' of maximum light is just smaller than it would be otherwise.