So after reading many different articles and browsing multiple forums I am still left confused on myths vs facts of SW ich. My main confusion lies in the truth behind the presence of the parasite in our systems. We QT fish and say that if after a certain amount of time of no disease than the fish is disease free and add it to our DT. However, mostly with tangs, people point to them and call them ich magnets if in a too small tank, poor nutrition, or any other stresser. I always thought the purpose of QT the fish is to stop the introduction of disease to our DT, so if the fish passes the QT why would a fish after 6 months develop ich? It should never be in our DT to begin with and if it gets in there anyway why bother doing a QT for a fish? Long rant but main question is does ich live unnoticed in the majority of our DT for years and years much like its cousin freshwater ich and only become a problem and cause an outbreak when there are stressors to the inhabitants?