Do you HAVE to get sand?

Question
Do you HAVE to get sand for hermit crabs? If so, how much? I heard you need a good 2 inches. Will any sand work? Does it have to be "Hermit Crab Proof"? I want sand but my Mom says it's "unnecssary". I have gravel (washed in hot water and is NOT colored. It's natural) it's about an inch or two of natural, washed gravel.

Thanks for Reading!
Patty! =)

Answer
Dear Patty,

You don't necessarily need sand. Gravel or Sand works. It can be any sand, and even beach sand. Two or three inches is fine. Gravel is one or two inches fine. If you want to buy sand just go to where you bought your crabs or a local pet store. Bye.

-Jenna