UPDATE
I did one round of Furan-2 but I ran out and couldn't find any stores that were open over the holidays that carried it locally. So I switched and started treating with Kanaplex. I dosed according to the directions on the package with water changes before each dose. I've done three treatments and the anthias' fin is the same. All of the other fish are looking great.
I've been feeding food soaked in Metroplex as well but the fish really don't like that food and typically spit it out. I don't think they got much metro.
I was thinking of doing a water change and then running a little carbon to remove any residual antibiotics and let the fish be for a week to see how the healthy fish react. If the healthy fish don't show any symptoms, I'm thinking of adding them to the display (that would be in about another 10-days or so) and treating the individual male more aggressively. I was thinking of going this route because I don't want to unnecessarily expose the otherwise healthy fish to antibiotics.
And, if there's another medicine I should try, please let me know. I have melafix and can get enough furan-2 to properly treat or I can go an entirely different route.
Thanks,
Z