This is my first air purifier and I LOVE it! I am so happy I got this Clorox air purifier. I was thinking my room was probably going to show horrible particulate matter, as I dislike dusting, but I was pleasantly surprised that the air wasn’t as bad as I had imagined. It stays around 1-2 after it runs for a while; it started out around 5-6. I can can breath so much easier now, and my allergies aren’t nearly as bad.