My 2 cents... The best ich shield is quarantine with a copper treatment. I like Cupramine. I used to not quarantine. It was stupid. Quarantine is easy unless you have huge fish and after having two huge tank breakdowns because I didn't I'm never not quarantining again. As far as nutrition, just MAKE SURE YOUR FISH AREN'T STRESSED. That comes from water quality, tank mates, and nutrition. Feed them a high quality food (Hakari frozen, NLS) and feed them regularly so they're nice and fat (a fat fish is a happy fish) and that's your best defense against disease.
Things like garlic additives don't work. They "could" increase a fishes immune system but it's marginal. And every study of garlic used as killing ich involves injecting it into the fish directly (talk about stressing them). It does help get picky fish to eat, and I say go ahead, use it for that, but don't count on it as a fail safe.
Things like garlic additives don't work. They "could" increase a fishes immune system but it's marginal. And every study of garlic used as killing ich involves injecting it into the fish directly (talk about stressing them). It does help get picky fish to eat, and I say go ahead, use it for that, but don't count on it as a fail safe.