Angelfish with red pectoral fin?

[danajs]

One of our angelfish has had red at the bottom of his/her pectoral fin for around a month now, and we’re just wondering what it could be. He seems fine in himself in that he’s active and feeding, but we don’t know if it’s something to be worried/concerned about.

- pH is 7.0/7.5
- Ammonia is 0
- Nitrite is 0
- Nitrate is 0
- KH is 3
- GH is 5

Tank is heated to 26C with 2x Oase BioMaster Thermo 600 running.

Tank mates are:
- 5 other Angelfish
- 8 Rummy Nose Tetras
- 1 Rainbow Shark
- 1 Synodontis Petricola
- 10 Sterba’s Corydoras
- 1 Green Phantom Pleco
- 1 Tiger Pleco
- 1 Ancistrus Pleco
- 2 Vampire Shrimp
- Amano Shrimp

 

[Uberhoust]

I am not a disease expert but I don't think you have a problem. I looked at my angels and some have the red mark at the pectoral fin junction to to body more than others do. Essentially when the fish move the fin forward they expose the underside that is not well covered with scales. I suspect you just started noticing it as the fish gets older. I would watch the fish for behavior changes but he looks ok to me.