Hello, I currently have 4 fish in QT, believe they had ich on three of them but one looked like velvet (too many spots to count). I am checking my copper level in the morning and night. The other three fish a sail fin tang, porcupine puffer and domino damsel are still going good and eating. Last night (10pm) when I measured the copper (using Cupramine and Hanna Checker) it measured .42. This morning I woke up and the one died (the one I suspected velvet), I immediately removed him and tested the copper level again and now it reads .27. If he died during the night would he soak up some of the copper? I am afraid to add any. I plan on doing my daily water change but unsure what level copper to put it at now. Has anyone come across this? Any advice would be helpful. Treatment has been going on for four days as of today. I was raising the copper level up slowly since I began as not to shock the fish.