Hey everyone i have a question about ich. No none of my fish have the parasite i am simply just trying to really learn more about these fish diseases and pests so i can be ready in the future. Now I have read all the other stickies and what not on other forums about how fish get ich and the stages of the parasites life. I also have a pretty good understanding on the best ways to treat for this parasite, but what i am having trouble getting an answer for is.... lets say a aquarium that has never had fish or corals for I dont know 7 months ( again this is just an example ) so there is absolutely no possible way the ich parasite could be in the tank and a fish that has never had ich nor in a aquarium with it. I read that the parasite does not grow out of thin air magically, So the actual question....can a fish create the parasite itself when stressed? Or does the ich have to be in the system already waiting for a weak stressed fish to latch on to? Thank you for the help I love learning these things!