I agree here. Low stress and heavy feeding has worked for me in past. I dont quarintine and never have. Ich is like a flu to us. If you are stressed and malnourished it may kill u. If you are healthy and well fed you will feel like crap a few days and get over it.
Breaking down the whole tank and catching them all and throwing them in hospital tank is more likely to kill them from sickened fish being stressed.
Like sauce said a uv sterilizer heavy varied diet and try not to mess around in tank for a couple weeks and they will be fine.
Ich isn't like the flu at all lol. Its not even remotely similar on any level.