Hello, hope your torts doing better by now, either way you must seperate them. NEVER put a new tort in with yours till you are certain its healthy and parasite free(stool). As far as the new one, is it larthargic? does it move around? discharges? Dehydrated? If the tort does not appear to be healthy with normal behavior I would recommend bringing it to a vet asap. If it does come up with something make sure you tell the vet yours was exposed to it. Good luck and hope it works out for you and the torts!