We must disengage one end of the diffuser, to remove another piece of white plastic, drawing with your fingers, to put water ... half of which will never be used as a stop broadcasting sensor when the water is below the mark. What makes you lose half the essential oil put in !!!
In short, personal, I think it's galley, and not at all practical or economical ... It's just aesthetics (why the lights are pretty, there's nothing to say).
