I just bought 3 purple pincher hermit crabs, two from a store in the mall and one from petsmart. Folks in the mall said their crabs don't require salt water, in fact, it will kill them. Folks at petsmart said yes these guys do require salt water. I'm confused... can anyone help me?

Definite answer:

Hermit Crab Key To Survival Freshwater And Saltwater

And this provides some good information on the care of Hermit Crabs:

HERMIT-CRABS.COM

Is there a species of land hermit crabs that do not require salt water?