What causes a few flower petals to brown?

[King_of_orchid_growing:)]

I think the problem may be water related. Without photos it's kinda hard to say, but there's good reason to assume it may be water related.

With the Brassia I really doubt there'd be an issue of too much light, idk. The Phal quite possibly, but not the Brassia. A light meter reading will take care of understanding this issue.




The technical term for "the petals are only the bottom two in the back of the flower", is - lateral sepals.

Orchids have 3 sepals and 3 petals. The labellum (aka lip) is a modified petal.