I had one that got gradually skinnier, less active and one day I found it dead stuck to a powerhead.
I tried garlic inffused nori and veggie wafers, but it only cared for film algae, constantly grazing on the glass, rock and equipment. Even the hair algae was ignored 99% of the time.
From my later search through the forums, it appears to be a hit or miss fish.
It either grows fat and happy eating pellets or it stays very selective and slowly wither away.
It is a shame, since it is an extremely personable fish.
I would advise against getting one if you don't have a large tabl with tons of rockwork and several kinds of algae.