Here's my opinion on using sand for substrate. I've used it for 18 years now and I've NEVER had an issue with it. I only use it for adults, not babies or juveniles. People complain about the risk of impaction, blah, blah blah....if your gecko is eating sand then YOU are doing something wrong with it's husbandry. A healthy, well-fed gecko that gets all it's vitamins from gut loaded and/or dusted food will not eat sand. And a healthy gecko that gets a mouth full of sand while lunging after a cricket can easily pass it out. And as long as you have a moist hide for the gecko to gain moisture during shedding you will not have to worry about retained shed on the tips of the toes.