I feed my tortoise a spring mix and/or butter lettuce. Recently I found him eating his Repti-Bark substrate ( forms part of the substrate along with coconut coir) This is a sign of malnutrition and less minerals in diet. He has a cuttle bone. Some of the other foods are harder to find (except for the hardy kale). I also mix in a little carrot once in a while. Any suggestions. I do now he needs a mix and I do posses a list.