QT everything if you like what’s in the big tank. One bad experience that can be avoided. I have a 29g biocube running continuously as a frag tank and QT. Whole thing with black box light I cut the top for cost 200$. Everything goes there for six weeks. Fish get strong eating new diet not getting picked on. Corals get observed closely. I’ve never medicated and some fairly sick fish have come back. Two wrasses and a pair of clowns live permanently in QT may someday act as early disease detectors.
so QT or not: up to you (an excuse to buy a second tank)(avoid disaster).
so QT or not: up to you (an excuse to buy a second tank)(avoid disaster).