Fire skinks question

[Dragondan]

Question... How much soil should I use in my fire skinkn enclosure. Just got him last Friday and he is all hiding all the time .I'm wondering if he has to much soil in the tank

 

[illuminis]

I've had mine for about a year now and I still rarely see her. I was told that a hidden skink is a happy skink. Only time I see her is when she's hungry (2-4 times a week) I have about 3 inches of substrate with plants, hide and water dish.