yellow tang died

[vince]

Beth, I'm sorry to let you down after helping me out with his/her eye problems. But I just had to post this because it seems so weird to me why he/she died.
Tang was doing fine in the quarantine tank, I did about 7 days of maracyn 2 medication and the pop-eye/cloudy eye went away. It was eating fine, swimming normally so I decided to put it back in the main tank.
The next day,it started to act weird. You know when smaller fish is eating the parasite off of your bigger fish, the bigger fish holds still sideways sometimes? Well only, yellowtang was suspended in midwater sideways acting so weird. After few hours, it started to get stuck between the rocks. So I moved it again to the quarantine tank and now, it's dead.
what happend? Did I make a mistake I should'nt have? please help me so i dont do it anymore

 

[beth]

You haven't let me down, you did the best you could. These creatures are fish and we can only do the best we can. It is impossible to know the right solution for every given circumstance involving our tank, and particularly our fish. Tangs especially, and particularly yellow tangs, are hard fish to keep. Next time, you might want to leave a sick fish in the hospital tank longer. Yellow tangs are very skiddish and sensitive to changes. Also, you did aacclimate him back to the main tank, right?
Anyway, you might want to stay clear of tangs and surgeonfish, as they are disease prone fish, and do tend to be difficult fish to keep.

 

[vince]

.. *sigh*