Thanks to everybody's advice I now have a beautiful 20 gallon cycled tank with several waterbabies. My crab is molting every two weeks! Please see photos attached.
Is it a really young crab? I can't tell size from the pictures. Molting every other week sounds like there's a contaminant in the water - unless it's a fairly young crab. Did you ever allow any tap water to get into your tank?
Yes, he is a very young crab. No contaminants in the water. No I do not use tap water. I mix my own water. I've work with hermit crabs too for over a decade and the molts in young ones are the same. My crab is happy and healthy.
