A. The gurgling noise that you hear and water sitting in the tubing is because there is extra condensation in the tubing from your humidifier. The humidifier setting is too high for the temperature in the room, meaning, inside the tubing is warmer than the room temperature causing extra condensation. I recommend reducing the humidifier setting, or another option is to add heated tubing, but be aware that heated tubing will need a prescription. Another thing to make sure is that your CPAP is lower than your head, that way gravity can stop the water from moving down the hose toward your mask.
For more information: How to Avoid CPAP Rainout

