Cory Catfish swimming upside down

[Hyzenthlay]

I did a 50% water change , which is more than usual bc I've been dealing with cloudy water. I did it as I always do, but for some reason my cory catfish are both upside down. Alive but not swimming and floating. I have 2. It's a 20 gal long so I did 10 gal. I don't know if I over cleaned or what, but please how can I save them?

 

[Rfinner]

I did a 50% water change , which is more than usual bc I've been dealing with cloudy water. I did it as I always do, but for some reason my cory catfish are both upside down. Alive but not swimming and floating. I have 2. It's a 20 gal long so I did 10 gal. I don't know if I over cleaned or what, but please how can I save them?

It could be that theyre stressed. They need groups of 6 or more.

 

[Hyzenthlay]

They've always done just fine as a pair It was all of a sudden after the pwc

 

[Rfinner]

They've always done just fine as a pair It was all of a sudden after the pwc

Maybe some thing else has made them stressed? Other than that im not sure