Awhile back I had 2 mojarra shipped to me. One went in my reef tank the other in a stock tank that got very little attention. In a twist the one I placed in my reef didn't last very long while the neglected one is still alive today. Well the ato float for the stock tank got stuck open and the saltwater moved to fresh so a lot of bad is going on with it now so the surviving fish is in a bucket with heater while I'm slowly making the water saline again. Anybody have any idea why one wouldn't survive in a maintained setup or would it go down to bad luck.