I had a few recent occurrences of what seemed to be very fine black dust on my fabric mask liner. I feared the worst - mold. However, I have always cleaned my equipment weekly, and used distilled water, and changed the little white filter every couple of weeks, and there is no smell or sign of mold ...

I would like to give a huge "Thank You" to those who provided the guidance in this thread. I've been lurking in this forum since I started therapy (7 months ago). I've had my share of ups and downs. My biggest issue was mask leaks causing arousals when pressure had increased - very counter productiv...