I wanted to ask, hope its not a too silly question...Do you use the uv/heat lights up to a certain age? or is it all their life?

Hi Claire,

UVB is important for the whole of a tortoise's life. They use the vitamin D3 from the UVB to sythesize calcium into bone and shell growth whilst they are growing.

When adults they use it to maintain their shell & bone growth.

HTH
Darren