White flakes/scales on Phal roots?

[vlhart]

Has anyone seen this before? I noticed some strange white fuzziness on this phal's roots a few weeks ago. Kind of hard to get a photo of it, but this white scaley fuzzy stuff is on a lot of the roots. It almost looks like freezer burn.

Otherwise the phal is pretty healthy. Lots of new root growth since repotting in May. Two new leaves this summer both look good. The three oldest leaves look slightly desiccated despite a solid watering routine, so I wonder if that's related.

Let me know your thoughts!