I read from one of the members on this board about adding a small amount of mouthwash to the humidifier--What a nice smell while you are breathing---also helps keep chamber clean and will not damage it---dont put more than a couple of oz in like I did---The first time it was way too strong...adj as to your liking!!!--Whoever thought of this -- thanks!!--Sorry I cant give you the proper kudos----Steady ahi of 5.4---wish I could bump under 5