As much as I'm a sand advocate...
if the gecko is flat eating sand, having sand defications, etc, move the gecko(s) off of sand. ADDITIONALLY...
- are you providing crickets and mealworms dusted with calcium and also dusted with a multi-vitamin supplement (this will be done separately)?
- If not, why aren't you?
- If you are, what are you using and how often are you supplementing?
Typically when I've seen this occur it's usually a sign the animal is potentially lacking something dietary. My best friend and I have watched in horror with young, captive box turtles taking in mouthfuls of the stuff. These are usually animals he or I have received from owners that relinquish them to us or are improperly setup in local pet stores.
The occasional accidental mouthful is understandable, and almost always results in the animal spitting the sand out. But flat out eating it is a whole other problem in and of itself; this goes for any loose substrate.
I think you're also find your leo will be much more active off the sand as she doesn't have to slosh through it. They don't come from a loose sand desert and aren't designed to be wading through it.
Regarding the activity, got anything to back that up? My collection, that's varied in population over the years, says otherwise.
As much as I'm a sand advocate...
if the gecko is flat eating sand, having sand defications, etc, move the gecko(s) off of sand.
No I don't. That's why I said "I think". As in it's been my experience. AS for where they come from, they don't come from loose sand environments. They are generally hard surface dwellers. As nice as sand looks, it's not accurate to their natural habitat.