Microns and Water Filters

What do micron levels have to do with whole house water filters?

This is what you know: water goes through your filter and comes out cleaner. You know that when your drinking water has gone through a reliable inline water filter system, you don’t have to worry about unseen chemicals, bacteria, or pesticides getting into your body through inhalation from the shower or consumption through drinking water.

One aspect about your filter that you might not know is whether it is a whole house water filter. This type of filter is built to remove any imperfections that are found in your water. This process is usually done before the water even gets to your kitchen faucet. It is typical for a whole house water filter to incorporate carbon filtration. Another thing to know about whole house water filters is that it will protect the plumbing of your house from wear and tear. Because the water is purified before it gets into your house, that also lengthens the water heater’s life.

The lower the micron number, the more contaminants caught and purified.

Another aspect of a whole house water filter that you probably don’t know about is the micron level. A micron level is the number of micron sizes that the filter can eliminate contamination. The micron level is between .5 and 5 microns. A “micron” is a unit of measurement of the size of a particular unit of water contamination. A small pebble has a much higher micron size number than the microscopic bacteria that might be in your drinking water.

The Smaller, the Better

The lower the micron number, the more contaminants caught and purified. You should look for the micron level number when you are purchasing any carbon filtration water filter. This number determines how well the filter will process different contaminants. For example, if the filter says it filters contaminants of 5 microns, literally anything below the level 5 is passing through the filter. Many chemicals would be passed over.

A charcoal filter is commonly used in a whole house design for water filtration and, in some cases, in point-of-use water filters such as faucet or shower water filters. This type of filter works the same way as a carbon filter, except the contaminants pass through charcoal instead of carbon. Micron levels are also present in a charcoal filter.

If a charcoal filter can stop anything 1-micron level or lower, the filter is most likely to be able to filter out cryptosporidium and giardia. Both cryptosporidiosis and giardiasis are caused by these parasites that affect the small intestine and can result in symptoms like diarrhea, dehydration, stomach cramps, and vomiting, to name just a few. Remember a lower micron level is better when it comes to cleaner and healthier drinking water.

Therefore, micron levels determine how well a carbon filtration water filter will function. Most likely, if a filter only removes so much chlorine or so much lead, it is probably because of the micron level. The price of a good water filter with a low micron level will be a little bit more expensive than a filter with a higher micron level. A low micron-level filter will also eliminate excessive fluoride from your water.


Our biggest advancement yet, the OptimH2O Whole House Filter, is a first-of-its-kind system that filters down to 0.5 microns to reduce lead, cysts, PFOA/PFOS, chlorine, chloramines and much more. Designed with a giant, ultra-dense carbon block, this system is engineered to offer superior filtration compared to granular media. It also uses catalytic and activated carbon, combined to perform ion-exchange and sub-micron filtration for first-of-its-kind effectiveness.

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