Mysterious Red Lump on Congo Tetra

[Christhefishman]

Hey guys,

wondering if anyone might have an idea what’s going on with the tail fin of one of my young Congo tetras. Appeared randomly about a week prior to me posting this and seems to slowly be getting larger. Not sure if treatment is needed or if it will go away on its own since I haven’t encountered something exactly like this before. Fish swims, eats, and acts completely normal. 
 

planted tank with no signs of illness on any other fish. 
0 ammonia,0 nitrite, 20 ppm nitrate for plants, PH 7.6, moderately hard, temp is 79
 

thanks everyone!

Edited December 10, 2023 by Christhefishman

[Colu]

It could be a cyst or an injury to the tail fin that has caused localized inflammation what I suggest is quarantine and treat with aquarium salt 1 table spoon for 3 gallons for a week 

[Christhefishman]

On 12/10/2023 at 2:30 PM, Colu said:

It could be a cyst or an injury to the tail fin that has caused localized inflammation what I suggest is quarantine and treat with aquarium salt 1 table spoon for 3 gallons for a week 

Okay great, thanks @Colu! I was hoping you’d see this post! I’m happy that it’s atleast looking like inflammation from a minor injury and not some kind of parasite or start of a bad infection. I’m off to grab some more aquarium salt. Appreciate it!