Please help my pleco (mouth closed, not breathing normally)

[Colin_T]

I didn't read anything from the thread. First picture.

This fish is in shock of a sudden environmental change...

Nothing to do... but wait.

This started before the gravel was removed from the aquarium. It was probably triggered by high nitrates but I doubt environment is the issue. I have had plecos in bare glass tanks with no substrate and they were fine.

 

[Colin_T]

@MaloK Interesting. You reckon? I can't think of anything other than the high nitrates I discovered when he started doing that. He seems to be improving with water changes, but of course, correlation doesn't equal causation. Do you think I should stop that then?

Don't stop doing water changes. Keep doing them because he improves with the water changes.