Orchid bark fungus??

[Discus]

Fungus will often mean you media is really decomposing, and should be replaced with fresh. Phalaenopsis tolerate repotting quite well, even when in flower. Depending on your medium and growing conditions, on average, once every two years is about right for phal repotting.

Make sure to soak the new medium overnight before using it, and make sure it's an orchid mix and not regular potting compost!