Thanks for your responses, but I didn't run out of water a long time ago because I'm very faithful about filling the tank. If I fill mine up to the high water line, it lasts at least two nights or more. I just didn't check it last night, so it may be empty now. Even tho I've had the bloody nose, I haven't had any dryness in the nose or mouth, so it never occurred to me that humidity could be the problem. I was told to use distilled water only in my machine and I have a cover that I put on the opening when I take of my mask and hose for cleaning, so nothing gets into the water tank. I appreciate your reminding me about the dangers of stagnant water tho.
Jean, you're right, I think we started on this forum the same day and we're about at the same place with the cpap. It's been fun comparing my experiences to yours!