What goes in a hermit crab habitat?

Required things: 

1 Substrate at least 6 inches (or 3x the size of your largest crab) - children’s play sand mixed at a 5:1 ratio with damp (not wet or dry) coconut fiber

2 Pools - 2 - saltwater and freshwater - holds at least 2 cups each - ladders - they are not going to drown as long as they have a safe way in and out. 

3 Heat mat covering entire top half of the back of tank - we recommend Beanfarm or Reptilebasics

4 Sealed lid - 100% sealed with no ventilation

5 hides - caves and structures to hide in

6 shells ~ 5 appropriate size/shape shells for each crab

Optional things:

1 bubblers or filters for pools

2 led lighting - no heat lights, but daytime lighting is recommended 

3 Food dish - unable to tip over

4 climbing options

5 wheel for running

6 isopods and springtails