The cons of quarantine

[kien]

To set up a QT tank in a pinch I just take live rock and some water out of my display tank and put it in the QT tank.

I haven't purchased a fish in ages but I usually play it by ear. A combination of factors like how fragile I think the fish is, how healthy I think the fish is and how healthy I think his previous tank mates were, etc. Either way, it's a total crap shoot, unfortunately.

EDIT: And by "display tank" I mean my sump. I have a pile of live rock down there that's handy for QT tanks.

[Enigma]

My QTs have been hit and miss. I lost one fish during QT, and I've abruptly ended two QTs well ahead of schedule: one due to the fish's behavior in the QT, and one due to a major ammonia spike (getting that fish into the display was how I chose to deal with the situation). I'll keep doing it, but I am a bit apprehensive about it, now.