Shista, I'm so sorry for your loss -- and I'm sorry I didn't see this thread earlier!
I agree with TommieLynn about this fish -- Mandarins are one kind of animal that probably do not need to by hypo'ed in QT. Mandarins have a VERY thick slime coat as you already know, and they produce excess mucus when stressed. This excess mucus can actually become a health risk for the animal, because it will cover the gill opercula and prevent proper respiration. Mandarins already have partially enclosed opercula -- if you look closely you will see that they only have a small opening over their gills rather than a large gill plate. Excess slime for an extended period of time really cuts down on their oxygen levels.
Unfortunately I also had to learn this the hard way. As a point of interest, you should NEVER use the "botanical product" Kick-ICH in a mandarin tank....it increases every fish's slime coat, and was a death sentence for a Mandarin of mine some few years ago.
Since Mandarins already have a thick slime coat, they are less likely to be carriers of skin-borne parasites like ich. You can still QT them, but do so in a tank that is pH and salinity-adjusted to match your display tank. This way you can observe them for possible bacterial infections, get them used to your face in the glass, and most importantly you can begin to wean them onto frozen fare in a safe, non-competitive environment. I noticed you have a 44g tank in your profile. Is this the tank the Mandarin is going into? Do you have a refugium or sump attached to this tank? I assume you've done your research on the difficulties of this animal - you certainly sound like you have - so you probably know that 44g is pushing the lower limit of tank space for a wild caught mandarin.
Finally, I would strongly recommend that if you DO get a new one, spend a little more and look for an ORA captive-bred Green or Spotted Mandarin. These guys are more expensive than their wild-caught cousins, but they are already trained to eat frozen food, and they will not cause any additional harvesting pressure on the native stock.
Mandarins are really beautiful little creatures. A healthy Mandarin will flit around from one rock to another, hopping from point to point like a little jeweled underwater butterfly. They actually are fairly active creatures; even though they don't swim in the open, they are often on the move. If you feel you have a Mandarin-safe environment in your tank and can support the pod population (assuming you don't get a frozen-trained critter!), then I encourage you to try again. And don't forget, next time......post pics!!
