[papagimp]

Michaeldaly, I don't QT either, but uneconomical would be not QTing the corals, they have some form of physical damage from shipping/relocating and wind up with tissue recession or brown jelly infection and spread that to the rest of the tank, killing off many colonies in the process and having to buy new corals. The cost of a QT tank is a small price to save this from happening.

aufan, you are looking for anything "abnormal" weather it be hitchikers you don't want, or infection on the coral themselves. More than just parasites come in, could have fungal infections, bacterial infections, parasitic. Ect. ect. ect. The list goes on and on. I would recommend QTing for the standard 4-6 weeks as you would any fish. This would allow sufficient time to notice anything wrong with the specimen.

If you don't have a QT setup with appropriate enough lighting, as a minimum, consider giving some corals the appropriate dip treatments as a precautionary measure.