My main tank has been fishless for about 5 weeks. I've been treating the Q tank with copper(should have went with hyposalinity but didin't know any better at the time) Anyway I was dumb and was having problems with elevating nitrites in the Q tank so I did a couple water changes the first week or two with water from the main tank hoping some bacteria would transfer over knowing free swimming ick might as well but I didn't want all my fish to die from high nitrite. It's been 2-3 weeks since the last ick spot I've seen on my coral beauty, can I assume it is all dead and put the fish back in my main tank now or should I wait a little longer?