If you have a quarantine tank this is the time to use it. You have a few fish with him that are very prone to ich; especially the yellow tang and mandarin. A quick fresh water Dip will help, but does cause more stress to the fish. Garlic helps boost the immune system because the fish are attracted to the smell their for they usually eat whatever food you have soaked in it. Do a search on ick and you will find lots of info. Good Luck