Review on Guardian Technologies H920BL Ultrasonic Cool Mist Humidifier - 10 Hrs. Run Time, 210 Sq. Ft. Coverage, Small Rooms, Quiet, Filter Free, Treated Tank Resists by Megan Washington

I had one of these and my daughter put some essential oil in it or got "old water" in it and the mist smelled awful. (By the way, don't add anything but water and try to remember to drain the standing water from both pieces to let it dry.) I thought I'd bought the same size again, but it ended up being a much larger version . Note. Small compact model - H920BL. This larger size is perfect for working 8-10 hours all night, but it takes up too much room on my bedside table (for my liking). So I ordered (again) and found the smaller model (H920BL) which I prefer, although the humidified mist doesn't last all night. I also prefer the smaller model because the cord is detachable and it's easier to fill and not have to fiddle with the base and attached cord like the larger model. To prevent air bubbles from stopping the fog, it is best to place the base upside down on the water funnel (blue) after filling the blue part, and then place the whole unit on the table with the right side facing up. When I tried leaving the base on the table, pouring the funnel part into the sink, and then quickly "tipping/tipping" the funnel part towards it, it got air bubbles in it which stopped the mist and didn't make it work. So I move the base and funnel to the sink and the smaller unit with the cord unplugged is less cumbersome. Since I mistakenly got a bigger pad as well, it makes random, fairly loud gurgling noises all night, which I didn't like when trying to fall asleep. The younger is calm. At least my experience.