libbysmom from the Hermit Crab Association has made an important discovery regarding vinegar. She has been experimenting with unfiltered apple cider vinegar. The hermit crabs eat it with eager enthusiasm and often soak in the liquid. In the past, some crabbers felt that vinegar would compromise the exoskeleton by breaking down the calcium, but now there is some indication that it might prove to be medicinal treatment for limb ailments. More research on this is sure to follow, but at least we know that they can eat vinegar.
It should be noted that pickled items from a jar contain an inferior grade of vinegar. We recommend that you get a high-grade vinegar such as Bragg's brand organic, unfiltered apple-cider vinegar with the "mother" beneficial bacteria included which you can find at most heathfood stores and some general grocers.