It's great for butterfly fish since their natural eating habit is to pick at things. So stick some of this onto a piece of rock in your QT, or the bottom corner of the glass tank (which I what I did) and see what happens. Then after a few days, mix some Mysis or Brine shrimp into it and they'll start realizing this is food also and eat from the water column.
I've been a huge supporter of DD and most of my fish come from either there or LA, but feel lately they are just putting DD fish up without any general conditioning and cherry picking the healthy (essentially fat) fish that come into QM and selling them on DD before they are eating. My Multibar was so fat, and for it to not accept anything if it was supposedly eating at DD doesn't make sense to me. Turned down live clams, black worms, every frozen option available for 3 weeks.