Here's sharing what i did,
I bought a couple of rocks of algae to put into the tank when i introduce my tang. (Either red bamboo or the 'grapes'... My YT loved those.)
It'll prob last them a couple of weeks... by that time they will be nicely settled down and start snatching food from the rest of the gang.
I dont think by seperating a space by net and let it be quarantine in the main display is advise, the diesease might still be spread to the main tank... Hee... BTW i didnt quarantine my tang... just choose the healthiest and brightest color one, provide it with my best care and hope for the best! HAHAHAA!