You can bet I'll be doing research if I have to tackle an infection or parasite! I'm curious if it's good practice to treat new fish as a precautionary measure, before they even display symptoms. Or even using treatments like Stress Coat or other supplements?
There are a number of things to consider and the longer you tank the more you'll learn. Consider 30 days the minimum quarantine period. Even then in all likelihood you will not detect the presence of internal parasites if the fish are infected or are carriers. (fact) Worming is required (imo).
I treat all incoming critters to a full quarantine. Mystery losses are pretty much a thing of the past.
Great that you are asking and want to learn and not simply "learn the hard way".