We only use carefully selected substrates from around the world from sustainable, renewable sources that are then heat treated and sanitized. Some of the substrates will work wonders for pets that dig and burrow, while other substrates are just for walking on. Reptiles are found in typically three types of habitats around the world; desert, rainforest, and semi-aquatic and whichever type of reptile, Pettex has the ideal substrate available. Tortoise Bedding. Pettex Tortoise substrate has been created to meet the needs of tortoises originating from arid habitats; Particularly Mediterranean and Russian Tortoises. The substrate mixture is a mix of high quality top soil and sand, with added Calcium. Its texture and moisture retention replicates your reptiles environments perfectly. It is also suitable for many species of lizards that originate from arid habitats. Available in 10lt packs.