oh shots fired!
Well other than my snowflake eel turning into jerky and my Houdini clownfish I've only lost a hippo tang and an Achilles tang due to some mysterious reason.
Hey now your undoing all the brain washing I just did. But seriously though when have you seen a 18" naso tang? I'd say they probably average around 10-14" in captivity.
They're very different in shape and color so it will most likely be fine plus all the people I know with nasos have yellow tangs with them along with other tangs. I think you should go rescue the poor guy.
I have a 6' tank and my tangs use every inch so I can the need for a big tank. Most people I know with a naso keep them in 6' tanks I only know one person that's kept one in anything smaller but didn't you say your upgrading?
They need atleast a 6' tank maybe bigger as they mature. They're pretty calm for tang standards anyways. I'd say it can be done and I've seen it done plenty of times.
I can get all of those at my lfs for around $450 if I ordered online it would probably be about the and it would most likely qualify for free shipping.
I don't think this forum really has any "tang police" so your safe.
I really don't see that killing every single fish I have never done anything but float the bag and I have never lost a fish due to an acclamation problem. I think they are being suffocated because of the top on the tank.