Tang fighting ich

My tang has been fighting off this ich for about a month so far and it seems health it eats and swims like all my other fish do. I reduced the stress in my tank,I've been feeding it well with xtream garlic. It doesn't have the white little grains on the body but it has these faded spots now for the past week. Is the ich still on him or is he healing. Also non of my other fish have it. I have 150 gallon water lvl a are fine. Any ideas or suggestions please help!