Guppy with swimming issues

[UrLocalFish]

Hello all,
About a few days ago, one of my male guppies, was having problems swimming upright. he will flop sideways and try to correct his position, but ended up not being able to swim upright at all. there a swelling on the right side of his body, which is the side he's floating on.

He lives in a 29g tank with some other guppies, 6 silver tip tetras, 2 neon tetras, 11 pygmy Cory, and one oto cat. there has been aggression from the silver tips before, but no injuries have been caused.
the water parameters are:
ammonia:0
nitrite:0
pH: 7.5
nitrate: 02ppm
The temp is: 77f
I already gave him a salt bath. Does anyone know what going on?

 

[Colin_T]

need a 1-2 minute video of the fish swimming.
upload videos to YouTube, then copy & paste the link here.
if you use a mobile phone to film the fish, hold the phone horizontally so the footage fills the entire screen and doesn't have big black bars on each side.

 

[UrLocalFish]

Is this ok?

 

[emeraldking]

That could have some reasons why it's swimming sideways. Most likely a swimbladder problem. But ti could also indicate stress or water parameter issues. But looking at your water parameters, that won't be the cause. But yes, I do see the swelling on his side as well. Could be a swimbladder disorder by the look of it. The swimbladder could have gone sideways. But in that case, you can't cure him.

 

[Colin_T]

euthanise him