It's a long haul back from an ich outbreak and I think sooner or later most of us have to deal with it. I started my tank in 2004 and in 2007 introduced a puffer that caused an ich outbreak that killed all but my goby. I used Kick Ich which I had to order from the US. I added fish slowly, one by one and kept them healthy and I haven't had any problems for years (knock on wood). I swear half this hobby is luck and voodoo.

I broke my 65 gallons fish tank on February, so I got a new 75 gallon in March. I think that made the fish stressed out caused to have ich. I don't think I am able to set up a quarantine tank if I get new fish, my place is very small there is no room left even for a small rubbermaid container.

I just had an ich breakout about 3-4 days ago. I kinda saw it on one fish but thought it wasnt anything(foolish mistake) then all a couple days later I looked at my powder brown tang, and on his fins, there it was, ich. I added a cleaner wrasse about 2-3 days ago. I usually only see him picking at my unicorn tang, and sometimes he'll go up to the powder brown but I dont really see him picking anything off. My cleaner shrimp doesnt seem to pick anything off the fish.
Today I'm soaking every piece of food(Nori/pellets/brine/mysis) in SeaChem's Garlic Guard. We'll see how this goes. *fingers crossed*

Personally I would look at things that would cause stress to a tank. Thinks like off parameters, lack of oxygen, oh so many things.

Others will dispute this, others may agree, but I am a believer that you always have ICH, but if you have a healthy system, then the fishes immune is able to fight and don't succumb to ICH. Daniella3D has valid points if you wish to go the quarantine route, I myself don't quarantine.

What I am scratching my head with is that you lost everything. This shouldn't happen, even with ICH... So what is off that the fish didn't like and hampered their ability to survive (Besides the ICH)? I personally think you have another underlying issue that is aiding things.

Sorry for the losses!

That may have done it. With the new 75 its like setting up a new tank. You probably had a cycle and depending on the amount of fish added the cycle couldn't keep up to the load.

+1 Amen to that!!

When was the last time you added a new fish?

I would like to have creditable prove that "...ich...Some even resist hypo-salinity treatment."
For me, hypo always work on ich. If hypo doesn't work on ich, it usually means salinity(SG) is not on target. SG should be 1.008-1.009 (or salinity 11 - 12). Or you don't hold the salinity at that level long enough. 4 to 5 weeks should be sufficient.

If you can do something PLEASE don't wait till the end like me. I was crossing my fingers untill I saw the last 4 fish struggling with their life in the last few days. I knew that was it. I hope you are not attached to your fish too much. Some of the Canreefers had met me, I can fool people with my strong outside look, but they don't know inside I am the most weakest one. I know I am going to become mentally crazy waiting for 10 weeks to put the new fish in. I can't stand looking at my empty tank right now. If not because of this tank related to someone and something which is sentimental for me, I would probably just shut it down for good.
The last time I bought a new fish that was when the first 2 fish had died for no reason. My Nemo died, I decided to replace him because my other female clown stopped eating. I thought she was grieving, I went to J&L got another clown but I had to return the next day because the female didn't accept it. I don't think that new Nemo I bought brought the ich into the tank.

Nothing against the store I love the place great service products and choices, but iv never had a fish survive from jnl. all my inverts did fine equipment is great but 2 died of ich a flasher wrasse and an indigo dottyback and another vanished after 2 days a randalls goby. the 2 died of ich didn't last more then 4 days I even tried the seachem paraguard dip with the dottyback guess my point is it's very likely that clown brought in the ich