when i get a new tang, i put my seaweed on a clip and watch to see if they go for it..if not, i get the seaweed soggy and crumple it up underwater.. it will send pieces of it all through the water column.. they normally go for it after i do it once or twice....i have also put the seaweed clip right next to where the tang hangs out in the tank, even if it is at the bottom.. they normally pick a hiding spot when they are new and stay around there.. if the seaweed is floating right around where it hangs out, they will nip at after a while.