Oh, I overlooked that one. Yes, there is a chance it would introduce parasites. Hybrid is correct in pointing out chances are the tank may be repeating nitrogen cycle. I would advise against placing any fish there until you make sure the water conditions have stabilized. You don't have a backup tank for the new arrivals until everything has settled?KMKN;3339100; said:The wild fish was just introduce today. Isn't there is mostly likely some other kinds of illness introduce?