Ich is in fact something every fish has...it is whether it is active or not and typically develops or activates from stress. It may just be your tank triggered it.
I wouldn't normally comment on these threads, but I feel it might be helpful to insert a bit of information here. Saltwater "Ich" is caused by the ciliated protozoan
Cryptocaryon irritans. It is a living parasite that irritates the fish and causes infection.
For a fish to have an infection, the protozoan must be present. It is possible to exclude this pathogen from an aquarium, system, or facility. In the case of a
Cryptocaryon-free aquarium, no amount of stress will cause Ich to show-up on a fish (other bad things could happen of course!). It is also possible for a fish in an infected aquarium to remain healthy -- only showing signs of infection after a stressful event.
Think about malaria (or take your pick of pathogenic diseases) in humans; no amount of stress is going to cause you to come-down with malaria if
Plasmodium isn't present (interestingly, both Ich and malaria are vulnerable to some of the same treatments!).
We regularly send-out live fish to be analyzed for specific pathogens and have yet to get a positive result from any fish in our hatchery facility. It's hard to prove a negative though, so we are always careful to keep stress low and monitor constantly.
I only say this because I feel that many of the MTRC members are friends. Mario, please imagine my reaction to reading your thread title after working hard to send a great order and for many years to build a successful business that hinges its reputation on quality animals, it is scary! If you have any questions about your fish, please feel-free to contact me or anyone at SA; we would be pleased to answer your questions or help you with a problem. We like to get feedback (good or bad) so that we can work to improve ourselves and our relationship with customers and hobbyists.
Matt