more is not better. particles that size will not be small enough to enter the cell and kill the virus. and there is no such thing as 2,000PPm the particles would be too big to do anything. I have tested 1,000 PPM from inovative labs. and tested them they were only 50PPM, my meter doesnt lie. its all BS and hype. what these manufactures say. 5PPM from all the sites, and Science studies, is all you will ever need.