Sick knifefish, something is up.

[Hendre]

Video shows condition of this fish. Since another knife died off this one seems to be on a decline, it is spitting out food and looking really bad. For no reason that I can deduct. Fish has been in my care for almost 3 years, was fat not too long ago.

Params:
Ammonia: 0
Nitrite: 0
Nitrate: 10-20
pH around 6

I haven't observed any aggression lately, nothing more than the regular occasional nip that they do. Neither of the other too directly attack him when he's nearby so I don't think it's that. The fish just seems emaciated.

Considering moving said fish to a 10 gallon (all that's available) and feeding it up with brine shrimp and frozen foods. At a loss with what to do here. Any ideas?

 

[kno4te]

Looks skinny and below a little swollen. Would move to a 10g and try feeding chopped up earthworms. Add a little Epsom salt 1tbsp per 5g. Can you get any metro or levamisole Hendre ?

 

[Hendre]

Knife is recovering well and seeming to be okay. Unfortunately the remaining two had issues, I now sit with an apparently dead fish. Went from tattered fins to barely alive in 24 hours... At an absolute loss on what to do

 

[kno4te]

Think you gotta get a larger group to spread out the aggression.

 

[benzjamin13]

Yeah...they need to be in groups or singular. Have you tried treating for parasites? I usually find with sunken stomachs and/or skinny fish, it might be a parasite.