Because 2 weeks isn't sufficient time for some of the infections to present themselves. The fish will be stressed when relocated and it needs time settle and be observed.
Quote :
http://www.reefkeeping.com/issues/2004-10/sp/feature/index.php
So, how long do I have to wait?
Ahhh, impatience. No character trait is more likely to kill aquatic pets than impatience, although laziness (which is related) comes in a close second in my book! If the time consuming process of curing live rock and cycling the aquarium was not enough to teach patience to the aquarist, a properly run quarantine will. There is no getting around it. For an effective quarantine, the new inhabitants must be kept for a minimum of one month. I feel so strongly about this that I would tell you not to waste your time if you can't commit to this amount of time. Time would be better spent learning to catch and remove all the fish from the main display for when an outbreak of a parasitic fish disease is encountered. Waiting that comparatively short period of time can be rewarded with the peace of mind of knowing that the health and well being of your pets has not been jeopardized. Given that most of the animals kept in reef aquaria have lifespans from decades to centuries, a month to help ensure their longevity is inconsequential. Furthermore, the proposition of holding an animal for a month will also enforce the notion that a quarantine tank must be a well-thought and designed simple system that does not cause more harm than good. Too many quarantine tanks are makeshift operations with conditions about equivalent in function to the shipping bag of water in terms of stress and water quality. By following the practices in this article, quarantine tanks should accomplish all the functions required of them.
Click here for larger image Click here for larger image
Both of these Maroon clownfish appear to be suffering from Brooklynella infections. Quarantine is
definitely recommended for fish in this condition. Photos by Steven Pro.
Note that the one month minimum period is for a trouble free quarantine. If the tank has been treated with medications at any time, the countdown does not start until after the treatment is finished and the animals are in perfect health. Realistically, that means some specimens are going to spend two or more months in quarantine due to the time it takes to complete a course of the medication or the treatment protocol. Again, I can't caution aquarists enough. There are no shortcuts here. Anyone trying to dissuade you is probably just trying to convince you (and himself) that what they have been doing for years works fine. Don't be pulled to the dark side. The lure of simply tossing new fish and corals into one's tank is attractive, but the Fish Disease Forum is littered with individuals who bought into that mentality. It simply doesn't work in the long run. Eventually, the pets you bought and cared for will end up paying the price.
