At the risk of writing a novel... she has had bladder issues for a very long time, and her wen grew uncontrollably until she was completely blind.   
  
They've been on a strict diet of shelled peas 2x a day for awhile now and that has kept her buoyancy in check. However about a month ago we went on a cruise and I guess she vacuumed up so much food from the auto-feeder she basically lost buoyancy control again, and by this I mean, she floats upside-down. (She's been an over-eater since day 1)  
  
About a week ago we noticed she wasn't really trying to eat anymore, and she just spent 100% of her time floating upside-down.   
  
2 days ago she thrashed a bunch during the morning feeding and none of the other fish would eat, so I removed her and put her in the hospital tank. No feeding and no change in buoyancy or behavior so I figured her QoL has reached 0. 

In case I need to do this in the future, I documented the dosage of clove oil, in case anyone in the future finds this helpful:

In a 10 gallon tank:

5 drops of oil mixed into 1 cup of water - I stir vigorously before adding each bit

1/4 cup of solution @ 7:50 no reaction, floating in place

@ 7:55 no reaction

@ 8:00 started slowly moving around

@ 8:05 no reaction back to still

@ 8:10 no reaction (added to filter)

@ 8:15 slowly swimming (like 30s/lap)



1/2 cup @ 8:20 to filter, no change

1/2 cup @ 8:25 to filter, no change



10 drops / cup



1/2 cup @ 8:30

1/2 cup @ 8:35 - Activity increase, faster breathing, twitchy swimming, mild splashing



Still again, still breathing - Probably considered “asleep” here



20 drops / cup



1/2 cup @ 8:40 - Still no real signs of distress. 

1/2 cup @ 8:45

1 cup @ 8:50 - Slowly swimming in corner against glass

1 cup @ 8:55

Breathing slowed, gills still moving, lets me push her around, no reaction to stimuli (light / touch) 



Breathing very slow @ 8:59

Gills seem to have stopped at 9:01

1/2 cup w/ 20 drops added after gills stopped. 



Waited 5 mins before removing her from the tank. 

There was never a period where she seemed to be in distress, she just slowly stopped swimming. Hopefully this post helps someone else in the future.

Had to euthanize one of my oranda today. Goodbye Goldie :(