Size of the house

Hermit crabs always like to have a big home. They like to burry themselves in the sand and hide especilly when molting. I think...[If I haven't already said this] perfer to have a 10-20 gallon aquarium or bigger depending on how many hermit crabs you have. I have 3 hermit crabs right now in a 10 gallon and am looking for a 20 gallon. [It's kind of getting crowded!!]