Fir bark is fine as a substrate too. Over here we call it "orchid bark", if it's the same stuff.
An impaction from aspen shavings will not show up on an X-ray. The vet should have the proper feeding tubes and syringes and can push a load of mineral oil or Vaseline down there. This will hurt nothing if your tortoise is not impacted, but could save its life if it is.
I don't know how you could have much humidity with an open table and all those lights. Do you have a hygrometer? It's probably pretty dry in there.
Another thing that might help is keeping them a bit warmer at night. 70 is on the cool side for small ones. If he does have an infection of some sort, warmer temps will also help him fight it.
An impaction from aspen shavings will not show up on an X-ray. The vet should have the proper feeding tubes and syringes and can push a load of mineral oil or Vaseline down there. This will hurt nothing if your tortoise is not impacted, but could save its life if it is.
I don't know how you could have much humidity with an open table and all those lights. Do you have a hygrometer? It's probably pretty dry in there.
Another thing that might help is keeping them a bit warmer at night. 70 is on the cool side for small ones. If he does have an infection of some sort, warmer temps will also help him fight it.