Hermit crabs can be used as an integral part of your aquariums cleanup crew (CUC), but they have become quite the debate as to whether or not you should be adding them to your saltwater aquarium reef, or coral tank.
While crabs are great additions to cleanup your tank, they can also become a nightmare to some people.
They will knock over coral frags, and can become snail eaters if you do not have enough shells in your tank.
You have to take all of the information and decide according to your own tank needs whether or not you will be keeping them in your saltwater tanks.
Hermit crabs are crustaceans that do not grow their own shells; this means for you that you have to provide your hermit crabs with additional larger shells as they grow older.
They will molt, which means they will shed the outer portion of their shell and become larger through every molt that they go through.
The main complaint that people have about hermit crabs is that they knock over coral frags, and eat their snails to get their shells.
While it is true that hermits will in fact eat your snails, they usually only do so when there is not an adequate supply of empty shells for them to choose from.
Another major problem with hermits is that they are considered "bulldozers" in the aquarium, while they will knock over small frags of coral that are not glued down, they actually do not go out and intend to knock over things in your tanks.
This can easily be solved by using either super glue for soft corals or epoxy for stony corals and glue the corals to your live rock.
Hermit crabs are a great addition to your clean up crew, they scour your tank for uneaten detritus, and can remove it from places where fish can not get at, do not write hermits off from the beginning they also make cool creatures that lurk around the bottom of your saltwater tank, and are iconic in the saltwater community.