Before you choose a micron filter for well water, it is essential to know what’s the impurities need to be filtered. Usually well water source has many contaminants includes Free Chlorine, Heavy Metals, Bacteria and impurities of rust, sand as well as kinds of organisms and chemicals.
Among all the above Bacteria and Organisms as well as Chemicals are most commonly-see contaminants. They share an average size of 5 micron. This point makes 5 micron filters is one of the good choices for well water filtration.
For another parts of impurities like rust and sand, 40 micron filter named spin down sediment water filter wound be the alternative option replaces usually 5 micron filters. The difference between 5 micron filter and 40 micron filter is that you may see 40 micron impurities in eyes sometimes while 5 micron impurities is usually invisible with the naked eyes.
In a conclusion, 40 micron filter is good option if the well water source do contain much more large particles of river sand and rust. Relatively speaking, if the well water does not have too many large particles contaminants, then a 5 micron filter is enough to filter out normal sand and rust as well as some other dirt.