My experience...
My experience...
I'm just getting over a case of ich in my system (new) too. On 4/21/11, I added all my tangs (yellow (2), purple, desjardini, achilles, powder blue, and hippo) and foxface to the display tank (370gal) to let them establish their hierarchy. The foxface, yellow and hippo were in an existing 90gal tank and I never quarantined them. All the others were QT'd for a minimum of 6 weeks or so and looking good when I added them. I went out of town on a family emergency two weekends later, and when I returned, the hippo, powder blue and achilles were completely covered with ich. I had forgot that 1.5-2 years prior, the hippo had a dozen or so spots of ich that went away (or so I thought). The stress of the move must have allow it to take hold and infect the other fish.
I was devastated. Fortunately, I don't have any coral or inverts yet, so I moved all my liverock from my sump (200-300lbs) into at 75gal tank that I took offline from the main system. All the rock in the display tank was recently "cooked" so I left it in (not that I could get it out easily anyhow). I proceeded to take the system (now 400gal total) to sg 1.009 over the course of 12 days (that's another story!). It took two weeks before the last outbreak of ich had subsided. I was sweating bullets during that time, because the achilles and powder blue had severe outbreaks, but kept active and eating. Throughout the hypo conditions, I performed 40 or 50 gallon water changes every 2-3 days to stay ahead of any water quality issues.
Everything survived and I am now raising my s.g. back to 1.020. The 75gal tank has been fallow since 5/15, so in the next week or so, I'll bring that back online too.