Most disappointing Livestock Purchase?

[Skimmin]

For me it has been two Naso tangs. I purchased two over the last two months. One lasted in QT for approx 2 days and the other about 3 weeks. The one of three weeks hurt. I was starting to feed by hand and making a new buddy and then... DEAD. I've given them a break for a while. Maybe try in another 6 months or so. The first one I believe was really sick from the get go, but the second one had me baffled.