Know what? I agree with goingpoor. Everyone has theories of how to do this and how to do that. Know what? Do what works for you in your house since the environment in each setup and room they are set up in is different (A/C in the home, ambient lighting unrelated to the tank lighting, number of people creating carbon dioxide in the closed up home, other house pets, etc.) All these things affect the tank even if you may not think so. If your methods work, great. If not, try something new. It sounds like goingpoor has a system of adding livestock that works out for her. Kudos!
I have QT fish before, tried acclimating them for 2-3 hours, and treated for all kinds of stuff before adding them only to have the crap not work.
This will make people cringe, but it works for ME. I hang the bag with the new fish in the tank. I add stress coat to the bag and use a turkey baster to add about 25ML of my tank water into the bag every 5 minutes until the water temp is equall. Then I add the fish and discard the water (and the bag too...) I have not lost a fish since doing my "what the f*ck" method. Oh ya, I do have a sock filtration setup before the fuge and am running a 40 watt UV and am cycling the water by it getting 100% kill on parasites. Only bad thing is it killd the good stuff too. Between that and protien skimming, I go through phyto like it is beer!
Flame if you want, but it works for me. I have even put one of my co-worker's soldier fish in my tank for a few weeks with signs of ick and immediately treated the food with garlick and did not use anything else. The fish did fine and none of the other fish caught it. The thing is back home with his master and doing well now.
Let the flames begin.