You can use a mixture of sand and earth for a substrate when housing baby sulcata tortoises indoors. Even so, You may as well use a mixture of cypress mulch, orchid bark, and aspen mulch. Furthermore, You may also use substrates like coconut bedding or peat moss for their enclosure. https://sulcatatortoisediet89566.madmouseblog.com/14267034/facts-about-sulcata-tortoise-facts-for-kids-revealed