Sorry to hear that Steve, I use Kent Iodine in concentrate of 1 drop per 5 gallons of R/O water for my Vampire crabs (completely freshwater). I have a few pieces of busted up scallop shell in the gravel to raise the Ph and put some minerals in it for their exoskeleton.
If you look at hermit crab water conditioner it contains a very small amount of Iodine, this is beneficial to molting in crustaceans. The guy who sold me the VCs also uses the Iodine in his shrimp and crayfish breeding setups. I am using the ratio he suggests for freshwater crustaceans NOT what is listed on the bottle which is geared for saltwater tanks. I have already had at least one male crab molt successfully using this water. I thought it was a dead crab until a couple weeks later I saw both male and female crabs in their tank at the same time.