In article , says...
First step would be to do major water change (up to 30% or 40%) with
good gravel vacuuming. All those symptoms are consistent with
problematic water conditions ... perhaps from over-feeding.


Agreed, but 30-40% hardly qualifies as "major" water change, does it?
My normal PWCs (week to 10 days) are never less than 50%,
and more usually 75-80%. The only negative factor there is that
it makes temperature matching a bit harder to get right,
but it can be done.

In cases where severe water problems are indicated (as here),
100% may be called for, which is the same thing as removing the fish
to a hospital, yes?

Gunther