Beards should not have sand as a substrate, especially juveniles. Sand, even if it says safe for beards can cause impaction. Children's play sand is fine, and cheap for older animals. I wouldn't go buying sand you get in a pet shop. I have found that newspaper works the best for babies. It is safer to use reptile carpet, news paper or you can even tile the cage (thats great for keeping there nails short). The reason they say sand is not suitable from young dragon is because they tend to be sloppy eaters. Cedar oils are toxic to most reptiles.