HCA: Hermit Crab Association

I just came home and went to feed my hermit crabs and noticed one of the water dishes in my crabitat has what I assume to be mold underneath it. Is this safe? If not how do I go about cleaning it? Can I just scoop the “infected” sand out?

Mold is not harmful to your crabs. Yes, you can just scrape off the fuzzy bits from the surface of the substrate.