Do I Need to Use an Isolation Tank for Molting Hermit Crabs?

Question: Do I Need to Use an Isolation Tank for Molting Hermit Crabs?

Answer:
Because a molting hermit crab is very vulnerable to stress and injury from other hermit crabs due to inactivity and the soft new exoskeleton, many experts advocate moving a molting crab into a isolation tank or "iso tank" during the molting process. Others leave their crabs to molt in the main tank. A third option is to isolate a molting hermit crab within the main tank. It is really an individual choice, and the most important thing to remember is that the environment of a molting hermit crab is critical no matter which method you use.

Isolation: as long as you set up an isolation tank with good conditions (especially heat and humidity) this is a good option as it allows a hermit crab to get through the molt without the potential stress of being bothered by other crabs. It does require having a second tank with accessories, as well as careful observation of your crabs for signs of molting. However, sometimes you will see signs that molting is coming and move your crab, but molting will not happen for a while so you may end up isolating him or her for a long time. See "What is an Isolation Tank?" for information on setting up an iso tank.

Modification: you can use a smaller tank (e.g. a plastic tank) inside the main tank, which makes providing the same heat and humidity as the main tank easier. Place a deep layer of sand in the bottom and provide food and water as for the isolation tank.

Leaving Molting Crabs in the Main Tank: the main advantage is that your crab will not have the additional stress of moving to a new tank at an already stressful time. You also do not have to worry about maintenance of multiple tanks. However, this does leave your crab in a vulnerable position and sometimes your other crabs may attack a molting crab.

When crabs are left in the main tank for molting, some owners will use a cut-off 2 litre pop bottle to provide protective barrier around molting crabs. Cut the top and bottom of and sink the bottle sides into the sand to surround a molting crab with a protectve fence from the other crabs, especially in the sensitive post molt phase. It is a bit harder to make sure the crab has access to food and water this way, but you could use small dishes (such as half shells) as a temporary measure. Be sure to remove the bottle as soon as the crab's new exoskeleton hardens and he surfaces so he can get around the tank.

Special Cases:
-Even if you are watching, you can still be taken by surprise by a crab molting unexpectedly. Never disturb a crab which is in the actual process of molting. You can sink a cut off pop bottle into the sand around a molting crab, making sure the other crabs can't get over or under it. Once your crab has shed the exoskeleton and had a bit of time to recover, you may be able to scoop him very gently place him and his molted exoskeleton in an iso tank, but only if necessary. I prefer to leave mine in the main tank and not disturb them during the process at all.
-Occasionally a crab will molt on the surface, in which case he or she should definitely be isolated (at the very least, use a cut off pop bottle around the crab). A crab who molts on the surface is extremely vulnerable to attacks from other crabs.

Go To Hermit Crab Molting FAQ for more on molting hermit crabs