Proper substrate for monitor lizard?

Argo, my Roughneck Monitor, is in a 75gal that is currently using newspaper. He really tears it up after I set it up all nice for him, he's fed outside his tank, so what would be a better substrate?

I use a mixture of ground walnut, happy frog organic soil and sand at about 6" deep. It makes a good burrowing substrate.

I agree with Lokielani, or something that's beening used to is Sani Chips. Just depends on the cage, remember they need humidity to shed and sani chips, and news paper you have to spray them alot, on a sand soil mix it'll hold humidity in it's self. Another thing on of my friends in Europe told me was aspen mulch, not the dry stuff from pet stores but from lawn and garden stores but find it in organic.

I actually use shredded aspen, I used a dirt sand mix for a while but at the time he was so small that he would burrow and we could never get him out, then we switched to sani chips but I did not like them because the hymidity was hard to keep with them. The shredded aspen is awesome. Holds hymdity and he can still borrow into and under it. He seems to love it and its easy to keep up with.

once i build my next enclosure for mine i think i'm going back to sand soil mix, trick i learned was build them a underground barrow and make it so you have a viewing point and a way in like a top that opens.

I used crushed walnut shell for a long time, and just misted him and he had a huge pool, but now that he is so much bigger it was hard to keep the humidity up so I switched to the dirt mix and he loves it!