Wrong using of humidifier will greatly increase indoor PM2.5

    You can not  directly add tap water into the humidifier. Because the tap water contains trace elements, such as magnesium, calcium, etc.It is easy to produce white powder, not only the pollution of indoor air,it is  also harm to human health. 

    Improper humidifier water will greatly increase indoor PM2.5, see using laser PM2.5 detector SDL301 test experimental video:

Improper humidifier water can aggravate the indoor PM2.5