I'm sorry to hear about the trigger. I would NOT put them in the DT. My rule is to never move fish in with others if there has been a death in the group due to unknown reasons. What about going the water change route? Change multiple large water changes in the QT, get the water conditions good, and then see how the lionfish does? If it turns out to be a disease, at least your DT would be protected.....I'm using hanna checker. Copper Power at 2.5ppm. Unfortunately the trigger didnt make it. I doubt it was flukes as I completed 3 rounds of GC recently. I even did a FW dip on the corpse to be sure. I did a water change. They seem less stressed. Although the lionfish used to eat heavily and come to the front of the tank but now its become quite shy. Not sure if it got spooked during my water change. My 30 days of copper ends in about a week. If everyone is eating, would it be safe to put them in my DT? Or I should observe for another week or so? I was thinking it would be good to pull them out of full copper into the DT.
Jay