I put fish with ich in my tank all the time. I never treat for ich and I never lost a fish to it. If the fish is healthy and eating like a pig you will be fine. When I see ich on a fish I donââ"šÂ¬Ã¢"žÂ¢t panic itââ"šÂ¬Ã¢"žÂ¢s nothing. Other things like disease I would worry and qt and do all the hocus-pocus, but for ich I let it run its course. A new fish with shipping stress will be susceptible to ich, but once in a stable environment and well fed the ich will go away. If the fish is sick and unhealthy, not eating, ich will do it in, but if you see a fish that unhealthy you would probably not buy it. Neon gobies and cleaner shrimp are your fish best frends.