Fish have been in qt inevitable lost the two that were showing signs the worst, but the other three so far so good although I noticed my tang has these darker colored spots on him is that normal when treating for ick, got a hanna copper checker and it read 2.24.
It may take as much as 3 to 4 days for the ich trophonts on the fish to begin dropping in number. Sorry, I don't see what you are describing on the tang....