Injured Betta

[2198Lindsey]

I got this betta about 2 weeks ago, he’s been living in my 49 gallon community tank with about 20 neon tertras, a clown pleco, many snails and 7 albino corydoras. The tank is pretty heavily planted. Monday when I woke up and did my normal rounds checking up on everybody, I noticed his mouth looked bloody. I can’t exactly tell what kind of damage was done, but he’s obviously had some kind of injury on his mouth and possibly his gills? I removed him immediately and put him in a quarantine tank with some salt hoping to help heal whatever he’s got going on. He was very active before all of this and he’s still swimming around fine but kind of lethargic I checked on him today and he’s starting to lose a lot of his color. He has been in a dark, quiet room in his quarantine tank so could that account for the dulling of his color? Any ideas what could’ve happened? I’ve never noticed any aggression in the tank between any of the fish and in the weeks leading up to this incident. Is there anything else I should be doing? 
 

Ammonia:0 

nitrites: 0 

nitrates: 10ppm 

I’m unsure of the water hardness, sorry. 

Ive attached a picture of him from before all of this, you can see the dark mark on his upper lip that looks like a mustache. I also attached screenshots from a video from Monday when I first noticed it and today where he looks much more pale. 

[Colu]

If he swim in to something in the tank he could have internal injury I would keep treating with aquarium salt  how much salt are you adding

Edited January 27, 2021 by Colu

[2198Lindsey]

I used the level one recommended on the Aquarium Co Op website, 1 tablespoon per 3 gallons. 

[Colu]

I would keep up with 1 table spoon for 3 gallons for 1week if it gets worse I would Treat with maracyn or maracyn2

Edited January 27, 2021 by Colu

[Mr_Manifesto]

That is a very strange injury.  Is there any kind of reflection in the tank where he was attacking it and damaging himself in the process?  Seems like the type of injury they get from 'fighting' with other fish but none of the other fish seem like they even care to fight with a betta, which makes me think he's attacking his own shadow/reflection.  Something to look into, but definitely looks like an injury.