The Scarlett Hermit Crab is a valued cleanupcrew addition sold instore here in Columbus, Ohio. It acts as a algaepicking hermit crab that polishes rock, helping reduce maintenance and improve water quality. Stock 12 per 5 gal in a balanced reef or fishonly system for best results. Difficulty: Easy. Provide spare shells to prevent fights. Dripacclimate and maintain stable salinity for longterm health.