All water that comes in contact with your hermit crab must be dechlorinated. Most cities add chlorine to their water supply. Some add chlorine and chloramines to the water. Unless you have contacted your water department and determined if they use both, you should use a treatment to remove both. In the past, it was enough to let water sit out for 24 hours so the chlorine could evaporate out. That no longer is sufficient because chloramines will never evaporate out. A bottle of water treatment is under $5.00 and will last for years. This is a small price to pay for peace of mind.
Stresscoat is also a dechlorinator. Stresscoat should NOT be added to your crabs drinking water.
Chlorine and chloramines cause burning on the gills of a hermit crab and will eventually kill the crab.
