Can you give us some more info. Like temps. In your case air/water. Even humidity. I hope he didn't eat some moss. If they get stressed by some reason,lets say getting picked up or handled extremely at that size. It lowers their immune system. Do you use light,calcium with or with out D 3. Do you dust with vitamins. He needs time to digest. So let me have all the stats. Btw welcome to the forum.