Wendy wrote:

Hi Nell, if it were my plant, I would cut the spike off, put it in a vase.
Unpot, remove any soft brown mushy roots, check for bugs, wash with Physan,
put cinnamon on cut areas & repot in a good draining mix. Also stake to
secure the plant.
Cheers Wendy

Thanks, folks. This is probably all good advice and I shall see about
putting it to good use, today, if possible.

As for it not getting enough water, it gets the same as the rest of my
phals - daily misting and water once a week with orchid food. However,
the sick one is in the smallest pot and perhaps that's one of the
contributing factors. May also explain why so many roots are outside the
pot.

The new leaf it is putting out seems very firm and healthy, however, so
the plant can probably be saved.

Thanks,
Norma