Tortoise Substrates
Suitable substrate materials for Tortoises are many and varied and it is amazing how strongly some people feel about exactly which type is or isn't suitable. Options are chipped or shredded hardwoods (which have the advantage of being fungal and bacterial resistant as well as being slightly aromatic), natural and crushed calcium sands, blended sterile earth/sand mixes, hemp and pelleted grasses, expandable substrates and orchid bark chippings.
We have kept many species on a variety of materials and find that juvenile Mediterranean Tortoises and Horsfields are best on chipped beech with perhaps aspen in the hide / bedding area and tropical rain forest species on orchid bark chippings and / or expandable substrates.
Once sub adult to adult most tortoises are fine on just about any of the above and in fact benefit from a couple or more different substrates in their enclosure as they are stimulated by the differing textures allowing them to exhibit natural behaviour's.