Ultrasonic vs. evaporative, which should I buy?

Ultrasonic models (most of the picks here) are quieter and cheaper but can produce white mineral dust if you use hard tap water, so distilled is recommended. Evaporative models like the Levoit 6000S and Blueair InvisibleMist self-regulate at a natural humidity ceiling and don't produce white dust, but they require filter or wick replacements. Specialist humidifier communities tend to recommend evaporative for whole-home and ultrasonic for single rooms.