You are supposed to change your BlueAir HEPA filter every 6 months. There is a display that tells you when to change it. I decided to see how long I could use my HEPA filter before changing it. I judged the effectiveness using my AirVisual Node. Today my air purifier finally struggled jeep my bedroom below 50 AQI. Hence I changed the filter today. Below is my HEPA filter … [Read more...] about Changing BlueAir HEPA filter