Figuring out how tight the mask needs to be, takes a bit of time. I think you will see that sometimes the fit might change from night to night. I would say about 90% of the time I don't have to change it, but items like facial hair, congestion, sleeping position(mine isn't always the same) have an effect. Trust me, you will eventually get used to it... And don't worry, the mask does not need to be hermetically sealed in order to work. You will also find that over a period of time, the seals at your 90% adapter to the hose will get worse and worse, only to work fine the next night, no matter how many times you remove and reinstall. One word of advise, is to be careful and monitor your water tank, if you have one. I don't have a cleaning system, and usually rinse my tank with soap and water every night. But even then, you will eventually build a kind of scum in the corners that can only be cleaned out with a wire brush or a q-tip. I am not sure who designed the tank but cleaning care was not part of the equation. Getting in the corners which are really tight can be a pain. my tank has ribs in all of the corners and the only thing I can get into those spaces is a q-tip and a lot of pressure. I will usually wash my mask 1 or twice a week. If I had some drool the night before, I will wash the next morning.