I Quarantine all fish, even those coming from other public aquariums. After the copper, I would run a course of prazi as well. As long as you manage ammonia and territorial issues, quarantining a number of fish at once is actually a lot more efficient than a few at a time.I was very tempted to just put them in my DT, but unfortunately I've suffered from not QT before so I have a habit of doing it regardless.
Jay