The tortoise life/terrain is awful stuff. I would ditch it quick. The least of the problems its caused is sore eyes but its also been involved in a lot of impactation cases leading to prolapse and fatalities
Just steralised top soil is ok (some mix coir with it) I used to use Wickses top soil but after 3 or 4 batches of it being smelly and black I just use homebase now, which seems fine.
You can use soil from your garden if it hasnt been treated with chemicals
