Mandarin Dragonet QT??

Hello everyone!



Unfortunately my tank started a battle with ich after I made a careless mistake and caused a major temperature fluctuation. My Kole Tang (who has passed away) was the first victim, followed by my Blue Spot Jawfish, and now I'm noticing it in my Picasso clown. I decided it was finally time to buy the supplies for a QT. I bought a 10 gallon tank and equipped it with a heater, air pump, and hang on the back filter. I used half water from my tank and half new saltwater and I plan on doing water changes once a day. I would like to treat all the fish with copper for two weeks and then leave all the fish in the QT for 8-10 weeks to let the ich run it's cycle and die. My problem is my Mandarin. I understand they can't tolerate copper medications and probably would starve in an unestablished QT. I read somewhere they can be left in my DT and the ich will still die out because they are immune and it can't feed on them? Is this true? I'm just trying to find the best option for my Mandarin because the other fish need to be treated with copper and I want to keep my DT empty until the ich has had time to die.