Some things to try to get the fish besides what is already mentioned in that thread.
1). Take the nori sheet and rubberband on to relatively small piece of rock rubble. See if will eat of this. Before you add to the tank. Place the nori after attached in a small container of tank water. Add a few drops of vitamins. Let the nori suck this in.
2). when feeding add seachem entice, its a banana flavor additive that simulates the smell of rotting carcass to fish.
3). Purchase some live macro algae from algae barn. Gracillia and ulva would be the two i would try. Feed like the nori attached to a piece of rock rubble.
The reason new tanks and difficult fish often do not mix is because, difficult often has to do with feeding. New tanks lack the diversity of life to sustain them.