[Otters]

Ok I've the QT tank running for 1 week, with a Longnose Hawkfish, and I need to clean it. I have read Steven's Pro article, and I didn't find it I should replace the water I took out with the water from my main tank or replace with the artificial mixed water. Thanks to whoever answers to this.

[wozza]

i would use artificial mixed water.

[leebca]

I covered that here: A Fish Quarantine Process

When the QT is first setup, it is fine (and even preferable) to use water from the display tank. (This is about the only use of old display tank water, I know of).

After the QT is in operation, all water changes need to be done with properly prepared and adjusted new (artificial or NSW) saltwater.

The philosophy behind this is that starting the QT, whether the water is carrying any disease with it is not that important, since the purpose of the QT process is to eradicate any/all diseases. But once into the quarantine process, the aquarist doesn't want to risk contaminating the QT with potential sources of disease. If the aquarist adds display tank water for QT water changes after the initial setup, the quarantine time must start over again and continue on for 6 weeks after that 'mistake.'