Why is it sounding like there's water in the line

Assuming there really is water in the tubing, there could be two causes.

1. Is the water tank filled too high? The right level is right below the MAX line.
2. Is the room too cold? The water is heated to a vapor, then travels to the mask. If the room temperature is too cool, the vapor may cool and condense back to water. As comfortable as it may be to sleep in a cool bedroom [my preference], I don’t want water in the tube where I could breathe it in [vapor, yes; droplets, NO] or have it spit out and wake me up.