A micron , also called micrometer, is a unit of measurement.
1 micron = 1/1000 mm (1/25,000th of an inch) is denoted by the letter µ.
Average human hair is about 75 micron in diameter and coarse dirt is about 40 micron . In filter cartridges, a micron rating refers to the smallest particle size in micron s that the filter cartridge is capable of removing. For example, a 30 micron cartridge will remove particulates as small as 30 micron while a 5 micron filter cartridge will remove particulates as small as 5 micron . The lower the micron rating of the filter cartridge, the tighter the filter and the smaller the particle size it can remove.
For sediment filters, generally a “nominal” rating is used, meaning that a high percentage of particles of the rated size are removed. An “Absolute” rating means that >99.99% of the particles of the rated size are removed. Rainfresh ceramic cartridges have a 0.3 micron absolute rating, meaning that they remove > 99.99% of particles as small as 0.3 micron .
I replace the QCAs (2) every 4 months last time I bought them they were $ 30.00 ea just bought 2 more a Home Hardware @ $45.00 ea.WOW looks like I will be removing this system.