turtles, uvb lighting

Question
I have had 2 yellow bellied slider turtles for about 6months and just bought them a new 200l 4ft tank. I went into the place where I bought my turtles to ask a few questions but i seem to get different information each time I go in there. We obviously need to get a new uvb light for the tank but we already told them the new tank has space for two long light tubes and is saying that i need to buy 2 uvb lights for the tank and can't just have a normal light that came with it in the spare space. Is it true you need to have 2 uvb lights in the tank or is he just trying to get more money out of me because the lights are expensive. As i only had one uvb in my current tank and they are fine as my current one only has space for 1 tube light.

Answer
Hello Sam,

No, you don't have to get two tube UVB lights at all.  Two would increase the UVB output obviously, but, if you get a light fixture that has reflective backing on it, then that will help increase the UVB exposure as well.
How close will you have the UVB tube bulb?  Which brand are you purchasing?
That is a great sized tank for your slider turtles!  Do you have any pictures of them & the set up?

Tracie