So After an ich outbreak in my fowlr a few months ago, I only had a 4" dogface puffer. Im leaving the DT fallow for 9 wks. I had QTd the dogface for 6 wks in a 29g, and he showed no signs of ich, no spots, no flashing nothing. So he probably had it subclinically? Going forward do you see any issues with treating with copper in QT for fish that can tolerate copper? I've just lost faith in simple QT even for extended periods of time.