If you have diagnosed Ick, only fish get Ick so the rest of your stuff in the DT is fine. To break the Ick cycle, the DT must have no fish, corals and inverts stay along with sand and rock, 72 days, no fish, nothing else will work.
So the fish, if they look, swim, eat and behave normally, just don't medicate the QT, but be prepared to take immediate action if something can be identified.
You need to decide what action and this requires ID. The pic does resemble Ick, but velvet is possible. Velvet kills quickly in 24/72 hours, ick is a much slower process.
The important part is to deprive Ick from its host ( the fish) no host, no ICK, but this takes at least 60 days but I would go the full 72.
Once we separate our fish, we can assist them easier in the controlled environment.
A small 20-40 gallon away is a great investment. I never cycled mine, just exchanged 10% water daily. I use hypo for delicates, (tangs and such) cupramine for the hardy ones like clowns.
Low stress well fed fish will either not get Ick or be able to survive it.
They will stay in the QT until the DT is ready.