humidifier issues

I seem to have a problem no one else is experiencing. My water chamber runs out of water completely every night and I wake up several times with a really dry mouth. It is set at 3 and I do not use a heated hose. anyone have any suggestions. thank you

Mouth breathing will cause excessive water use.

These things affect water consumption.

1...ambient humidity...missed by a lot of people. If your ambient humidity in your house is low then more water will be consumed trying to maintain whatever humidity setting a person prefers
2...humidifier setting..obvious
3...pressures used..higher pressures will use up more water
4...leaks...either mouth breathing leaks that are excessive or just large amounts of mask movement leaks. The more leak you have the more water gets consumed.