Some good aromatherapy diffusers include the PureSpa Essential Oil Diffuser by Pure Enrichment and the Riverock Essential Oil Diffuser by Deneve, according to customer reviews on Amazon.com. The PureSpa diffuser has a 5-star rating, as of July 2015, while the Riverock diffuser has a rating of 4.5 stars.
Both diffusers work by filling with water and adding four to five drops of any essential oil. Different oils provide different aromatherapy experiences. Users can buy essential oils pre-mixed to provide a certain experience, such as relaxation or bedtime.
The PureSpa diffuser cycles through four different colors to provide soft lighting and provides aromatherapy coverage that lasts seven hours per cycle. It covers rooms up to 250 square feet and operates by sonic diffusion, providing quiet functionality. In addition to providing aromatherapy, the PureSpa essential oil diffuser also deodorizes odors from pets and tobacco use, and provides hydration to support users with asthma or allergies.
The Riverock diffuser also covers up to 250 square feet. It works continuously for four to five hours, depending on the cycle. Deneve advertises the diffuser as a product that sterilizes, moisturizes and ionizes the air by producing a fine mist of water containing diffused oils. The Riverock diffuser also works as a humidifier if the user fills it with water and leaves out the essential oils. It features a soft-green light band and produces minimal sound.