Tank needs emergency overhaul, but crabs keep digging

[odelayheehoo]

I am desperately needing to redo my entire tank, but I have been putting it off for months because the crabs have constantly been going down when others come up, it's a never ending battle.

Right now, all of the crabs except one are up and about, and I am fearing that one or more of the others will dig down again. The substrate is extremely settled which means it's very shallow as well, and not to mention dry as a bone. It's been so long that it has settled down from a total of ten inches down to seven. I know that you normally need to wait for everyone to be up for a overhaul, but I am not sure how much longer it can go without new moistened substrate.

Thoughts?

[odelayheehoo]

I forgot to mention that all crabs except one small are big mediums and a couple large.

[curlysister]

I wouldn't dig. I would add some water along the edges to moisten the substrate. And you can add up to an inch of sub per 24hrs, as long as you don't pack it down.

[odelayheehoo]

I suppose that I could just add some substrate but I hate to bury everything that I have on it already, but I'll just fix that when I actually get to redo it.