Congo tetra sinking

[jschall]

One of my female congo tetras has to swim upward at a 45 degree angle to keep from sinking.

I read somewhere to fast fish for swim bladder issues (because they can be caused by intestinal impaction or something), so I haven't fed her for 2 days.

What else can I do? Do I just need to wait it out and see what happens?

 

[jschall]

Also, it looks pretty much normal. No bloating, wounds, discoloration or parasite cysts noticeable.

 

[jschall]

I think it just had eggs. I did a 5-day treatment of maracyn 2, put it back in its tank and it was still sinking (but a little bit less). The next day I did a big water change and now this morning the male congo tetras were going nuts, chasing each other and the female around, bright dominant colors on all of them.
Now they're still at it. I've seen eggs here and there in the plants and such, but I doubt any eggs will survive with my bichirs and knifefish in the tank. It still seems to be sinking a bit, but we'll see tonight or tomorrow when the spawning is done.