At what age should a hatchlings shell start to fully harden? my torts shell seems to have started hardening more since ive been able to take him outside for supervised visits to the kiddy pool,i was worried becuz his shell was still kinda soft at a year old even tho appetite is as good as ever and has energy,alert and looked great.I Feed plenty of fresh grown opuntia cactus (his favorite) im hoping the calcium in the cactus helps his shell harden more along with the fact that theres sun out and he gets more access to it these days..