Sick Danio?

[Okidoki]

Hello Everyone,

So I am new to the hobby and I am worried that one of my zebra danios might be sick.
I have 200L tank with some live plants that have cycled.
Ammonia, nitrite 0ppm (with as much certainty as much the liquid API test can give)
Nitrates 10-20ppm

Her top fin looks damaged and she also has some scales missing just behind the top fin.
She was stuck behind the filter yesterday, I had to help her get free.
So it could be just damage, but I am not sure and a bit worried.

She seems ok otherwise, eats well and likes to play the boss of the tank.
I have total of 5 of them.

Attached a picture of her.

Any help/opinions are welcome.

 

[Guyb93]

In my opinion your water is ok I always look to keep no3 below 20ppm others are a little more precise but i would say your within a good margin , hierarchy can change in an instant with shoaling fish might be just a change in the pecking order if she’s eating and your water parameters stay consistent I’d just monitor For changes