A 7 foot tank with glass cross beams on the top, 250 lbs of live rock over 60 corals grown into the rock makes getting the fish out impossible. As to qt, I qt'd all my fish. It is impossible (easy to say though) to qt every snail invert, clam, soft and hard corals, pods, mandarin fish, anemones, starfish, fuge materials an fuge clean up crews, etc. Lets play that out. I could set up a tank with metal halides to keep the corals. Say you buy six corals. Have a second tank for fish. But knowing that if you buy more than two or three you will be just about guaranteed that one will have Ich and affect all of them. So in 6 weeks we can add six corals and 3 fish, now we start again, now I buy some snails and a few more corals, 6 weeks later they go in, and 3 more fish. But I lost two fish in Qt, so I add one. Now I see a clam I want, so the clam goes in the coral tank for 6 weeks and 3 more fish. 6 more weeks of managing three tanks. Then you see a cool anemone,so he goes in the coral tank, and again Qt 3 fish. 2 make it this time. So we are 6 months into a very staunch Qt everything mode,and we have 6 fish, 12 corals, one clam, one anemone and some snails.
A decent stock on a 230 is 15 fish, 60 corals,a few clams,an anemone, 80 snails, a few star fish, a couple sea cukes, 50 hermits, a fuge with pods, macro and more clean up stuff. With the example above, it would take 1 1/2 years for the fish, and 2 1/2 years for the inverts. You did it, but then you find a nice manderin fish. He can't survive in a Qt. Do you add him? Then you buy some pods, those can't be Qt'd either. But the manerin needs them (I have never been comfortable enough to trust that my tank and fuge supply enough, so I add some every two months). You buy some macro to feed your vegetarians, that can't be Qt'd.
I point all this out because this is what it would take to do what you suggest. I mentioned that I didn't want to debate Qt stuff here, there are more threads than needed on that subject. I am asking people what their experience was when they have not been able to break down large systems. I'll put it here so that people can see that Ich can come from anything. All my fish were Qt'd for 6 weeks. My original fish came from my old 120 and were ich free, that's why I was able to have so many fish so soon. I did not Qt the corals, but was careful with what I bought. I didn't Qt my clams because I wasn't going to put metal halides and a chiller on my 50 gallon Qt. Nor was it possible to Qt my mandarin, and I choose not to Qt my $250 Helfrich fire fish. I bought two and gave one to my son, his didn't have Ich, and mine hasn't shown a spot, so I think its a safe bet I didn't get it from him. I have no idea how I got it, and I am not the only one to experience this. It is absolutely impossible to get all 15 fish out of that tank without pulling all the LR out and draining it down some. Just the firefish and jawfish alone would be impossible in a 7 ft tank that is 26" deep and has three horizontal glass braces from the back of the tank to the front. . Then, they won't fit in my 50 gallon tank, so where do they go? How many will die from the trauma. That's why I put the question here, and why I wanted to keep the thread focused on this type of situation. I have ozone, uv, cleaner shrimp and a cleaner wrasse. I am not wanting to sound rude, and I have been and always will Qt every fish I buy, but thats not what I was asking advice on. My tank is still doing great and none of the fish are showing any symptoms right now. So, back to what I am asking for advice on, what has been the experiences of people with large tanks that couldn't be torn down when ich is present.
Thanks, Guy