All current fish and all new fish need to be in the QT. Leave the tank fishless for approx a month. Turn up the DT's heat to about 82 to make the ich life-cycle speed up to help speed along the ich die-off.
Fallow time is 72 days, not a month. Increasing the temperature lowers dissolved oxygen and raises blood pH, so it is not a good idea for marine systems.
If the DT has nothing but Live Rock then it doesn't matter.
All current fish and all new fish need to be in the QT. Leave the tank fishless for approx a month. Turn up the DT's heat to about 82 to make the ich life-cycle speed up to help speed along the ich die-off.
If the DT has nothing but Live Rock then it doesn't matter.