basically a new fish will go through an acclimation to your QT tank... then go through the quarentine then through another acclimation to your display tank. Acclimations take a few hours, quarentines a few weeks.
Trust me... once you start plunking down the cash for all the LR
, corals, fish etc into the tank... the thought of adding something that could kill them all... will make you want to be sure it's safe before you do so. Especialy once you've gotten attached to all the fish and they way they come up to great you when you get home from work.