Shrimp and crab molts

Having had the CUC in the tank now for almost six months I have a question on the molting cycles for them. The reason I ask is it seems that everytime I do a water change with in a few days everything seems to do this. Cleaner shrimp, lobster, emeralds and peppermint seem to molt every two weeks. Just wondering if this was normal since I cant remember how often things shed their shells. FYI I do a 20 gallon water change weekly. I also dose calc every three days.

 

Generally, a molting crustacean is a healthy crustacean.

 

Yeah mine are healthy!!!!!

 

Normal. Also, the calcium doesn't dictate so much the molting. Its iodine. Which is replinished every water change

 

Thanks all just trying to make sure things are going according to plan.