HCA: Hermit Crab Association

how do people get their tank so humid without floods? i spray the tank a little bit and the substrate is already so wet but not humid

It might help if you describe other details of your setup. I've found that glass canopy lids really help. If have a screen lid, and you want a quick fix, you can cover it with saran wrap.

What are the humidity and temperature readings in your tank?
What do you use for a heat source?
What do you use for substrate?
What do you have for a lid on your tank?