ich is really unavoidable 1.
if u want a ich free system, u will have to QT everything even corals etc. it's impossible because some of the difficult angels CANNOT qt. like bandit etc. imagine hypoing and coppering a bandit.... it's already so difficult even with luxurious conditions and still want to qt. cfm die 1.
so the best way is to keep it at bay. not eradicate it.