I personally dont think its a lack of iodine. Adding Iodine to the tank will prevent infections, infection is not the reason for a molting death. What I have read when a molt death occurs it seems that the mantis can not remove the old exoskeleton, right. Which i do believe would be a calcium problem. What do you guys think? I'm no expert here. I'll start to do some resource on what takes place when a invert. starts molting. Like how does the exoskeleton comes soft in the first place? and then what happens after that. Then maybe We/I can figure out whats going on here.