Does Neon Tetra Disease Present as a Lump?

[cboatman]

Hi everyone! I have a neon tetra that I've had for roughly 3 months that, over the last couple of week has devolped a lump on his body. Does anyone know what this might be? Water parameters on are track and there have been no additions since I added my fish 3 months ago. We had a period of ich right after the addition, but that cleared up quickly. I'm worried that its Neon Tetra Disease. Does anyone else have any ideas? The other fish seem relatively healthy.

Here's other necessary information

Tank size: 10 gallons
pH: 7.1
ammonia: 0
nitrite: 0
nitrate: 20 ppm
kH: I'm not sure what kH and gH is
gH:
tank temp: 78


Volume and Frequency of water changes: bi-weekly, 30%

Chemical Additives or Media in your tank: activated carbon

Tank inhabitants: 5 neons, 4 glowlights, 1 emerald cory

Recent additions to your tank (living or decoration):
New filter, 3 live plants~ 2 weeks ago

Exposure to chemicals:
Primafix, melafix, salt

Thanks for the help!

Digital photo (include if possible)

 

[Fish-mates]

I've read that faded areas and a lumpy appearance can be a symptom of neon tetra disease.
About a month ago my 10 neons had reduced down to 7 and one of those had a strange absence of red in the centre of it's body and it looked as though it's spine was bent. Having already lost 3 neons - which I never found in the tank! - I was pretty freaked and decided to euthanase the neon. I then euthanased another neon I thought looked suspect although I wondered if I was being paranoid. The 5 remaining seem happy and healthy.
Good luck with yours.