I am sure sorry you lost the fish. Your posts indicate you are catching on. 30 years ago I started reefing, long before the internet. All I had was past FW
knowledge and books. I was also pretty poor, so I started by using 55 gallon glass aquariums with HOB
's. I started thinking it was impossible to have tangs without ick. I killed dozens of them before I got wise to the fact that tangs were a bit different than the other fish I was keeping. There was no Tang Police to warn me off, I would have listened to them! I hated killing those fish so much. Years later I built my 300 gallon that has now been running 23 years. The issues with ick disappeared. Happy fat tangs that are almost 10 years old was the outcome. Stress kills surgeonfish, just as fast as bad water will. In a smaller system, you are very lucky to keep one tang, much less a group of them. Just my opinion, but it's based on failing, then finally succeeding.