The Powder Brown has a reputation for being delicate/hard to acclimate/a finicky eater. Keep on trying mysis for variety, but mostly veggies for this fish...Nori, live macro (gracelaria w/b a nice start), and *especially* Spirulina. Pellets are OK - Dainichi Marine makes a wonderful pellet for veggie eaters called "Reef Veggie FX".
DO NOT feed these fish land oriented veggies like lettuce or spinich. IOW, if it didn't grow in salt water, don't feed it to them!! Why, you ask? Spinich contains oxalic acid which can cause crystals to form in the fish's kidneys (very BAD), and lettuce can and will clog the digestive tract in marine fish. If you don't believe me, ask Bob Fenner or Calfo.
As far as the PB not eating the Nori yet - with our tangs I found that sometimes it takes another fish that is used to eating "veggies on a clip" to show them how good it is. It may take a little while if there is no other fish to show him "the ropes". You can also try rubberbanding the Nori to a rock and putting it on the sand bed...this will usually help, as this is a more natural way for the fish to eat (picking algae off of rocks).
W.



