Swordtail side fin rotting

[Aspencer]

I have a 10g tank, Ammonia 0, NitrIte 0, NitrAte 10, ph 7.8, temp 24.7

I have two females and one male, maybe 8 to 10 tiny babies from two batches, 13 shrimp, and 14 plants. You can see my tank and history on my thread in planted tanks.

Yesterday I noticed that the side fin was half gone and white at the end, only one fin. All behavior is normal in all fish.

 

[Tasha]

sounds like possible aggression and nipped off?? or does it look fuzzy like some sort of fungus?

 

[Aspencer]

Welllll, it could be nipped I guess. It is half moon shapped with dead parts hanging. My two other swordtails do not have it. I tried getting a picture but it is almost impossible.

 

[Aspencer]

Update:

Fin looks the same, very active chasing food...babies and flake...

Will check water parameters in the morning and probably do a PWC