Check out
www.uvguide.co.uk for their recommendations regarding mercury vapour and compact UV lights.
Essentially, these lights shouldn't be placed in close proximity to lizards due to the very high levels of UV radiation they put out. The website will give you an idea of how close they can be used, plus this info should be provided on the packaging for the compact fluoros (its about 60cm for the Reptisun 10.0 from memory).
If you already have the setup, my recommendation would be to just replace the fluoro tube.
