Originally Posted by Minkota
The best way to set up a QT is to use some of the water from your display tank as it is already cycled and add copper to it (or slowly reduce the salinity if doing hypo). The recommended size is about 20g and long is better than tall. No substrate or rock, use pieces of PVC
as structure for the fish to hide in. Also turn the heater up to around 82 degrees to help speed up the ich cycle. Leave your display tank fallow for a minimum of 6 weeks.
Using the water from the main tank will not cycle a QT. The water itself isn't what cycles, as the BB that consumes the ammonia is in the sand and throughout the live rock primarily. Turning the heater up also will do nothing, as this method is only effective in fresh water. To the OP, there are many good articles on setting up a QT, and I recommend reading them. There is a lot of information as to how to do this effectively. And please just don't "add copper" or "reduce the salinity". Both of these methods are the 2 proven ways to cure ich, but are not as easy as this reads. There is still testing involved, and constant monitoring of salinity, PH, and ammonia. Hypo is very involved as well, as the salinity needs to remain between 1.009-1.010 for 2-3 weeks, and a refractometer will be required. Once again, please read some of the articles here on AA.. Good luck!