I recently bought 3 angels from my lfs and all 3 of them have this growth on their little stringy fins plus a small spot on their tail. In case you can't see in the pic it is slightly pinkish.
justonemoretank;3474927; said:It's not ich. I'm guessing fungus. Params are all right, correct? The addition of these fish could have stressed your biological filter, creating less-than-optimal water parameters, and so everyone's sort of having a hard time, and so they're more susceptible to fungus. Since your other fish are starting to exhibit this, I'd definitely check them. Something similar to this happened to my angels when I skipped a water change and nitrates rose. They were little fuzzy bumps on the spines of the fins.
Lupin;3476020; said:The "stringy" fins are ventral fins.
You haven't stated what your water parameters are. Please include tank size, tankmates, maintenance schedule, foods used, treatment used and other symptoms observed. The more details you can tell us, the better.