NetMax wrote:

All this advice is circumstantial. Fish bring all sorts of diseases with
them, either dormant or even just as carriers. I usually hold my breath (in
a manner of speaking) for about 3 months. In that time, most of what they
bring will manifest itself. The most experienced hobbyists can find
themselves in your situation.

Once you are past this 3 month threshold, and you have a good maintenance
plan in place, you begin wondering why you ever thought of fish as fragile
;~). hth

Yes, indeed. It does help to use medicated food like TetraMedica for the
first week, to limit the chances of opportunistic bacteria. But that
isn't a cure-all either, you'd have to control the handling of the
fishes in the entire supply chain.