I am setting up a tortoise table and have purchased an Arcadia 12% UVB tube 900mm long. I am not sure how high I should have the tube suspended above tortoise level, my table is 4ft long 2 ft wide and the uvb is 900mm long.

Please help?

About 10cms above your tortoise, a reflector is needed.

It is essential to buy from a breeder, as opposed to a pet dealer, in which case you will get all of the advice which you need.

I would halve the length of the table, until your tort. is about 7cm. Outside in summer, of course.

Tom