QT tank advice

[marblesab]

I've been doing more reading and research, and a major commonality is quarantine tanks. I understand the rationale, however I have never really had to set up a QT tank before (I've had nursery tanks, but I suspect they are slightly different lol) Anyway I would LOVE to know the basics and generally what kind of process you take when quarantining a critter. I read on the MB earlier today, that you don't necessarily want a filter on the tank. Now that just blows my mind. Isn't doing constant water changes going to stress the new critter out even more? Do you add new saltwater or do you take some from your established tank? If its the later, then aren't you going to throw your established tank out of whack by robbing its water constantly? How long do you leave them in QT for before adding them to your DT? For some reason, this above everything else I've learned - is just stressing me out more then anything.

Also - do you QT ALL live additions? IE: coral, snails, hermits, fish etc? or just fish?

Any advice or suggestions is appreciated.

One more thing- My DT tank is 27 gal, how big should a QT tank be?