If they are getting sun from 7-9am, I would supplement
them with UVB bulbs.

You do not have to use the mercury vapor bulbs with them.
These are actually strong. I do use them for my desert
lizard, Ichabod, as he requires very high amounts of heat
and UVB.

Get online to LLL reptile. The generally have the
Reptisun 5.0 priced very well. I have used these
on all of the turtles and think they are probably the
best for this purpose. You would need regular household
bulbs for heat.

Hope this helps
Linda