Tonights the first night

It sounds like your first night went a lot better than mine! Congrats. I can't imagine using it at a pressure of 20! Mine's at 13 and I think that's high. It's my understanding that you do have to empty the tank and rinse it with warm water and a mild soap every day (and then leave it to dry). This may be unique to my machine (and InteliPap from DeVilBiss) although my respiratory therapist listed it in her care list for all systems.