It's nice to start deep conversations regarding the treatment of ich. I'm not convinced quarantining is the only measure we can take. If it is true that simply bringing in corals/inverts can also bring in the parasite and they need to be QTed as well, then this would be painstakingly difficult for any hobbyists to keep a reef tank. Problem is if we need to QT every fish before putting them in the display tank, and qt every invert/coral, then that means we need separate qt tanks around the house. Corals can't be held in copper/hypo treatments, so they get their own quarantine tank. Fish need their own tank for hypo/copper treatments(if necessary). Also, many fish can't take copper, so now you need to have a separate tank for your butterflies, angels, etc. In addition to all of this, this forces you to put a fish one by one inside your display tank... causing aggression for territory. I just don't see QT as a full proof solution and I really think we should focus more on ridding ich, despite it's complicated life cycle, than preventing ich.