Do you/did you quarantine your new fish? That is really the only way to avoid it. I am definitely not an expert on fish disease so I'll let others more experienced in that arena chime in, but I know there are a number of avenues you can take. The simplist is to keep feeding your fish to keep him healthy so he can fight off the infection and hope that they both do (and that others don't catch it). But it may not go away on its own, and you may end up needing to remove the infected fish and place them in a quarantine tank for treatment until they are better. A quarantine routine for all new incoming fish is the best (and some will say only) way to avoid disease in your tank. Good luck!
If you can't get a QT going, then I agree with Jesse and fishwhisperer. Definitely try the garlic. Be careful, that stuff stinks and my wife won't let me use it now because I stunk up the kitchen with it.
Jesse is right; you should always QT your new fish. Garlic is mainly used to get the fish to eat. There are no hard facts that it will fight off the disease. If the fish are eating without using the garlic, then don't use it. Treating your fish in a QT would probably provide the best results. If you can't get a QT together at this time, keep them feed and healthy until you can. It may take a month or more to completely rid your display tank of ich.
thanks everyone. I only have a 7 gallon and i dont want to put the tang in a 7 gallon the spots on the angel were gone this morning, but the tangs sleeps for a while even after the lights come on so i never see her in the mornings. Im thinking since the angel's spots are gone that its not ich. maybe they just rub against the rock at night and im jumping to conclusions. But ill know for sure when i get home and look at my tang. Kevin if its not clear when i get home i might let you educate me on what your talking about. My girl is getting me garlic tonight