I had a very happy feather duster in my 30
gal. But I had nitrate issues and the cure was Nitrate destroyer, a bacteria additive that consumed nitrate and then died. That probably helped feed the feather duster.
I moved him to my 110 g with sump and my water quality is very good. So no food for the feather duster and he soon died. That's when I found out that large feather dusters like 'dirty' water. Too bad, cause they look cool.