The enclosures for adult pairs or trios are 45x50x40.
They just lay in the dry sand. Sometimes they bury the eggs under the hide, sometimes just outside in the open, usually near some branch or cork.
A big pile of disturbed sand is usually a good indication of egg(s) being laid.
Eggs are relatively big and very fragile. Digging them up requires a steady hand and some patience. That's why I prefer to give them just a few cm of sand.