QT tank should be a smaller tank (10-30g, dependig on # of different fators)
usually a hob
by itself will work (no carbon, just floss, maybe a ph for bigger qt tanks)
buy a sheet of filter floss, cut a piece that fits in your hob
filter, then place it in your main tank to seed it ( you'd want to disgard the floss after completing qt, then simply repeat steps)
no sand, no live rock, nothing more than pvc
monitor atleast daily, if not 2-3 times. keep extensive track of any bumps, spots, redness, discoloration, changes in behavior etc.
try to qt 3-4 weeks. at that point, usually any dormant sickness that is in the fish will appear.
although i dont necessarily disagree with fw
dips (it has its uses) i fell its prob best left for the expert hobbyists. you really have to be able to read a fish and know when/how long a particular fish needs in fw
before it starts becoming a negative issue. the beauty of qt tanks are that you dont have to treat for anything when first starting the qt. (unless you want to proactively treat, but im peronally against it). also it really gives the fish a good solid chance to calm down and establish a decent routine of eating and he can gradually adjust to the new life.