I had a tank wipe out due to disease and now I have tons of apitasia. None of the fish were known to eat these, no wrasses or butterflies. So not sure why these sprang up out of nowhere so suddenly? I would have a couple that I would blast with apitasia-x and that's it. I did do the fluconazole treatment recently for briopsis.
The only thing I thought was my lawnmower blennie was always scraping the rocks and kept them at bay although not eating them, they couldn't get established. Now I have rocks covered with them.
I recently bought some Berghia, not clear if they are helping or still in the tank. Maybe hermits got them? Might try some peppermints if no improvement soon.