Regal Tang ??

[Nano]

+1 sounds like the DT has it too, a bit strange that he is the only one getting it though

[gregzz4]

That's a really tough call as to keeping him or not

Just as you may get the flu when I won't, some fish have immunities to certain strains, and some don't. But apparently all lose this immunity over time

I'd think, from what I've read, that some of your other fish are most likely infected but it's not so easy to spot ie; in the gills

Personally, I'd run the tank fallow for 9 weeks and QT everybody with the hyposalinity method. First for the recommended period, then another 4 weeks of observation

Do it once to get rid of all the MI, then you'll never have to deal with it again
QT all new dudes for 6 weeks observation and dip everything new that you can do so safely with