“The average size of the openings between pieces of the filter media are represented in microns. For example, a 20-micron filter has larger openings than a 5-micron filter. Consequently, the 20-micron filter element will let larger particles pass through the filter than the 5-micron media would.” (Source – https://inspiredliving.com/ )
As a basic rule, the smaller the Micron rating the better!
Our Genuine Awesome Cooler branded 8 stage KDF Water Filter have a 5 Micron rating. This provides adequate water flow whilst effectively filtering out contaminants including rust, organic sediment, chlorine, pesticides, heavy metals, bacteria as well as any bad small or taste.