I got a Moorish Idol from J&L 4 month ago, he was badly infected with ick, quarantined for 2 month, he is now eating and has been transferred to display tank.
very healthy and has his long fin recovered completely.
Eating seaweed and all other foods.
You can see him here (pic #1)
http://www.canreef.com/vbulletin/showthread.php?t=97866
Rear fin has also now healed.
UV helps with this. But main thing is (i was told, don't know if this true) how fish was caught in the first place. If fish is
eating before you buy it you have a very good chance.
jmtcw