Melafix is a tree extract with natural antibiotic properties. It's great for minor issues, I use it as I would an antiseptic on a cut, to help kill any bacteria that could cause a 2ndary infection. But I personally wouldn't use it as a "stress reducer" any more than I'd put hydrogen peroxide on my skin without first having a cut.
This is exactly why I'm using Mela & Pima for my 3 little corys. If I notice something wrong with a new fish, I'll directly address it.You aren't treating them for a "stress reducer" you're treating to make sure that any unseen injuries do not get worse.
I'm not fighting a specific disease. I'm thinking about using mela and pima on 3 corys that I recently got while they are in a QT.
Fish can recieve small abrasions and scrapes from normal handling when moving from tank to tank. Hit a rock from being chased.. trauma from being netted.. You may not notice the small injuries, but they are often there. It is best to use a more mild medicine like melafix when moving fish to avoid larger problems caused by access to their body for bacteria and parasites via scapes or things you can't necessarily see. You aren't treating them for a "stress reducer" you're treating to make sure that any unseen injuries do not get worse. The stress is minimized because any injury the fish gets will not likely get infected.