Many will give their Phals about a 10 degree f drop in temp.for a couple
of
weeks.

That's the key. If you can't do that naturally, try to create a cool space
at night. You might set an ice bucket next to it, for example, or even put a
few ice cubes on top of the medium. Do this in late October/early November.
That should do it for you, providing it's getting enough light. I do
remember your description of the way this Phal is "potted". Interesting.

Diana