you should try the search function to find info about substrate if you want to read past threads. But to help answer your questions...I have used caclisand in the past and switched to sand (playsand from home depot)awhile back. I have kept and bred leos for over 9 years with no impaction problems. If you use sand you need to use caution! General rules to follow: keep calcium dish available at all times, watch temps carefully, keep a humidity hide available, keep fresh water available (clean daily), check fecal droppings for large amounts of sand and check the leo's underbelly for signs of blockage or impaction, keep a thin layer (don't pile it up!). Basically pay a lot of attention to your geckos and watch for problems. These are pics of some of my enclosures. The first uses 1/8 " playsand, the other pics are of the second enclosure with tile and sand substrate.



