[Lobster]

Ich isnt a 'disease' that you can just cure. Its a parasite, and as long as the fish is stressed out and conditions are favorable for the parasite to do its thing, it will. Garlic alone will not "cure" ich.

You have to first correct the conditions in your tank, meaning you must first remove whatever has caused your fish to decline to a state that favors the parasite. This is the stressor. This might be a chemical problem, a harassing tankmate, dietary deficiency, new to the tank... anything, but your first step in fighting ich is to remove this stressor.

Once conditions are again favorable for your fish, then you fight the parasite. Garlic is thought to cause the parasites to leave the host. I've had alot of luck with garlic myself, so I would definitely say it does work, once the stressor is eliminated.

If the stressor is still in the tank, feeding garlic is of little use, because conditions in the tank favor the parasite.