Just starting with chickens again....My Pullets will be 18wks next week, I've been collecting, washing, drying & crushing egg shells (store eggs) for calcium supplement in the future. Feeding some to my meal worm farm which I started for the chickens. Just noticed when I opened the container the smell of chlorine. Now I'm wondering if the store eggs; "Mainland Shell Protected", I live in Hilo, HI; are some way "treated"? Thinking of dumping this batch & wait until my Hens lay. In the mean time will be supplementing with Oyster Shells. They're on Home Grown All Purpose right now, when they start laying will give the OS. Any ideas whether these store bought egg shells are ok to give as supplement?