I chose the Serenity model because it will run for up to 8 eight hours, and I was looking for something that would run throughout the night. I like to diffuse a Respiratory Blend of essential oils at night because it keeps the airways open so there is less snoring and less coughing.
While it's a bit noisier than one of my other diffusers, it's half the price and the noise it does make it almost like a white noise machine. You hear the water bubbling around as it diffuses the essential oils into the air. This would be great for someone that lives in a noisy area.
The water tank holds 200 mL of water, and you just add 5 drops of essential oils to it. It seems to put out a pretty good mist. It covers up to 400 square feet, so it easy fills our bedroom, and would even work in a larger room.
The only thing I wish I could change is the Blue LED, which stays lit while it's running. I like to sleep in total darkness, so we just make sure to angle it so that the light isn't shining directly at us.
Unlike my other diffusers, it only requires water for cleaning, so it's pretty easy to clean the chamber. Overall, the GreenAir Serenity diffuser is a good value for the price. It's available for purchase on Amazon.com. You can also check out GreenAir on Facebook.