well i have had a small naso tang for a few weeks now and she had ich, but it has been cured for a week or so, but she isn't her normal color...she is really dark like when she usually gets mad, but its all the time....i don't whats wrong..she doesn't have her color yet though except for some orange on her lips and on her forehead
also try brocclie, spinach,greens, and alot of them .naso require a large established tank, if you do not provide these requirements it could have a tragic resaults
lettuce, iceberg i think. some lettuce is good for them. its better than algea. most crabs eat it too. im not exactaly sure, but i think its iceberg, it might be some other lettuce, just look it up, you'll find it!
iceberg would also work but dont limit yourself to just ice berg,naso tangs in captivity require alot of diffrent greens in ther diet.excluding.lettuce because of it unutritional value.