Make sure you place a fish already in your school in the tank.
I don't have a retail setting
Well, the only argument I have with your approach (if I understand it) is that you are treating all fish as if they are carrying bacteria and parasites. If I'm in the hospital, it's because I have a problem and hopefully they only treat me for that problem, and not all other potential illnesses that others may also have manifested while in the hospital. Your head lice example included "there are egg pods on the hair" - that's an observable manifestation of an infestation. If you had said "the kid was itching therefore it's head lice with no other observable signs" I'd say you jumped the gun.
I think waiting and observing can tell you a lot about whether a fish is healthy. If you want to add a scrape to that, that's fine. But medicating every fish as if it's infected seems like overkill. But that's the opinion of someone who has never quarantined a fish - we added all our fish at one time. The only other additions have been pond-born and they pass automatically.
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.