I just got a 20gal tank from a friend, including some red legged hermit crabs. Do I need to provide larger shells for it now or in the future? I've attached a not so great pic, the hermit crabs are about 1-1.5 cm with the shell. It seems like it might grow out of it soon?
I usually keep a few extras around for them to swap if they want and hopfully keep them from attacking snails for theirs. Dwarf's dont usually bother them though. Reef Cleaners sell shells cheap if you're looking for some.