It more than likely will at some point..best thing you can do is make sure your fish are fed a variety of foods, including garlic. This way they're getting the necessary nutrients they need and have a good immune system...When and if it happens, they have a much better chance of naturally fighting the ich. I think everyone here who has had a tank for more than a year has had to deal with ich in some way. The people who don't freak out and start dumping stuff in the tank are the ones who usually come through it ok..
I could be totally off on this, but this is the way I look at it. I don't dump chemicals in my tank. Nature doesn't so neither do I. I think the best way to keep a tank healthy is to do what nature does, provide clean water constantly. I do massive water changes every week.
Ich as much as we hate it, is a natural occurence. Nature has given the fish the ability to fight it with their immune systems. Whatever those chemicals are that manufacturers sell that kill ich IMO must stress the fish out in some way..Those chemicals aren't natural, the fish have never encountered them in the ocean, if they've never encountered them in the ocean, it must stress their system in some form or fashion.
Keep the water clean, the fish fat and healthy, and you've got a better than average chance of coming through an ich outbreak unscathed.
Again, this is just my opinion. I could be totally wrong.
