Kzang, as you may have figured out, I am totally against quarantining. I have written extensively on my reasons and even wrote a book. I also have the oldest tank and maybe the oldest healthy, spawning fish on here. There is a reason for that and it is the same reason I have never had to post on a disease forum since way before they invented forums.
But I think if you want to go for a normal, healthy tank without any quarantine, you need to get those fish healthy.
That would mean you would have to eliminate all medications put the fish in with other "normal" , not quarantined fish and feed what I consider the only real fish diet that can keep your fish living long enough to only die of old age.
That diet is food with living bacteria like frozen, or better, fresh or "freshly" frozen (in your freezer) food, like clams.
Live worms would be even better. No dry food. Not even if you put garlic or Selcon on it.
(By the way, don't do that)
Your ich infected fish are now starting the process to become immune because ich will keep up their immunity depending on how long you have been medicating. It is not the same with every fish or every dose of medication.
I personally would put those fish into your tank and feed what I said. They may die, I don't know. Sometimes people die after a hospital stay, it depends on what condition they are in and I can't see your fish from here.
But remember, virtually all fish in the sea have ich. They swim with it, breath it and eat it at every meal. It is normal and the fish were meant to do that.
Fish are perfectly able to fend it off as that is what they were designed to do. If we eliminate that, we will end up at some time on the disease forum. Don't believe me. Go there and see how many quarantined fish died from either ich or quarantine.
My fish don't die. But they need to maintain the health and vigor they had in the sea. Only the correct food and contact with normal diseases will do that.
It is very easy but you can't short cut it by trying to medicate. It doesn't work. You have to pick one method or another.
If you go with quarantine, contact Humblefish as he is the Quarantine, medication Guru. (And a friend of mine. )
Read this thread
The other way to run a reef tank (No Quarantine) I was asked by my friend Humblefish to start a thread on my practices of running a tank with no quarantine, hospital tanks, medications, dipping or almost anything else. It is "not" just to take a fish from a store and drop it in your reef...
www.reef2reef.com
I won't comment on this. If you want to go this route, that is your choice.