My bet is on the trigger. If the CB is threatened, he won't eat and its death to him. And if the QT tank is too small, not a good idea. You have to be prepared to spend significant dollars getting it cleaned up and eating either way. I would not use copper or a fresh water dip. BTW, you can NOT make the pH of fresh water = to salt water without harmful additives and then its not fresh water anymore, its an alkali of some kind. I would look for a lfs that can QT the fish and get it eating, but still, my bet is that trigger is going to beat him to death. No problem with the lion unless he is large and thinks he owns the world, but thats not very likely.