Ich will remain dormant until it sees an opportunity to attach to a weakened or stressed fish with generally lack of slime coat.
The reason powders in particular are ICH magnets is because they have a very thin slime coat compared to a lot of other fish, flame angels are the same, very prone to ICH. because of the lack of slime coat they carry. This is also why dragonets never get ICH because of their thickened slime coats.
I suggested a new addition may get it to rear its ugly head, because it is generally the most stressed fish, i wasn't suggesting that ich will rear its head just because you add a new fish.
70% of reef tanks carry ICH.
We are obviously on different pages
@beth which is fine, but after having an ICH out break shortly after the upgrade, moving all fish to a hospital tank, were 2 died within hours of catching and placing in QT.
Took my chances (12 hrs later ) added all fish back into the DT all covered in spots back into a comfortable,large, stress free environment and lost not 1 more fish to it.
I honestly believe the catch and move killed those 2 fish and don't believe 100% that they would have died in the DT.
All my fish are now ICH survivors, the only reason they got it in the first place was the stress of the move. As i said previously have recently added 10 tangs, including 2 x powder blues and a purple, known to be ich magnets and no sign of it re appearing.
Everyone panics with ich, you don't have to. They can survive. I have heard of people that lose whole tanks to ich and that unforturnate too, but their fish must be in some kind of weakened state. Keep pristine water, variety of food more often and hands out of the tank and they can fight it off. Ive proven that.
But I took my chances and it paid off, the stress of the QT with not rocks, hiding holes etc was killing my fish 100% not the ICH itself.