Isn't the problem with ich that they drop off their hosts, lay eggs and die, and then the eggs hatch and you start all over again. So, if you take the fish out and treat them, but don't treat the main tank where the eggs are, don't you end up with the same problem in another few weeks or so? I've seen it lots of times where it comes back worse than before. So, if that is the case, wouldn't you WANT to treat the main tank as well, where the young hatch and reattach to the host. I thought that was the good think about ECOLIBRIUM. It is safe for corals, inv's, LR, etc, and you treat at all stages. Sure you gotta spend some cash, but you gotta do that anyway when you treat them in a QT. ??