Tangs will eat just about any macro algae you have in the tank.
Dont take my word as the gospel. Reefrunner or Anenomen should be able to give you a definate answer.
If you have a tang and also wish to have some macro algae then its best to cultivate it in your sump or a refegium and then when the tang has eaten all of it out of your display tank to add more from the sump.
__________________ Remember dont tap the glass, your fish will think you're an idiot-Anonymous mother