Many people rely heavily on water softeners in their homes. But if you are an active outdoor enthusiast, you may have come across microfilters for water and you may be wondering how they work. I decided to put together this guide so you know what actually happens inside a water microfilter that allows you to purify safe drinking water.
A water filter designed for use in nature generally consists of three separate parts: an input hose, a central chamber containing the filter, and an output hose or attachment. First, the input is placed in a water source. Generally, it is recommended to use flowing water to minimize sediment or biomass that might be in the water. Most input hoses have some sort of basic filter to minimize sediment uptake though, so it is actually possible to filter pond water or even puddle water! More information on microfiltration can be found on Wikipedia.
The central chamber of the water microfilter is where most of the action is. Most water microfilters generate the force to push water into the filter by a handle or lever. Pumping this (generally about once per second) pushes water into the filter, resulting in water purification rates of about 1-2 quarts/minute. Other water microfilters, particularly larger camping filters such as the Katadyn Base Camp Microfilter, use gravity instead of a handle to pass water across the filter.
The filter in the central chamber of the water microfilter generally come in two styles and contain two elements. The actual filter itself is either glass-fiber or ceramic. These are developed in such a way that the pore size is generally about 0.2 to 0.4 microns maximum. This allows water to easily pass through, while bacteria (which are about 0.5 microns wide) and protozoa (about 1-2 microns wide) are prevented from entering the filter.
This ceramic or glass-fiber element also collects a certain amount of sediment from passing through the filter and might need to be cleaned regularly (especially after hiking or traveling) according to the manufacturers instructions. Typically this involves cleaning the outside or through special “backflow” setting that removes it.
It should also be noted that most glass-fiber filter elements can filter only about 200-500 gallons of water while ceramic filter elements can filter 13,000 gallons over its lifetime. Since replacement glass-filter elements are about half the cost of a new filter, microfilters with ceramic filter elements such as the Katadyn Pocket Water Microfilter often end up being a better investment over the long term.
After the water passes through the ceramic or glass filter, most microfilters have a charcoal element that is either user replaceable or embedded in the filter itself. This charcoal serves to do three things: it can remove unpleasant tastes from the water, removes unpleasant odors, and removes dangerous chemicals that may be found in the water (such as DDT, a dangerous insecticide that is still used in some developing countries).
Once water is free of sediment, bacteria, protists, chemicals, odors, and tastes, it then passes out of the filter through an output hose or attachment. This allows the water to be placed in a container or water bottle for drinking or cooking. Certain models also directly attach to a water bottle for ease of transfer and is a convenient feature to look for.
Our View of the Best Water Microfilter
Hopefully this guide has given you some insight into how do water filters work. If you are looking for a quality water filter, I recommend looking at the Katadyn Pocket Water Microfilter. This is a small, well constructed water microfilter with a ceramic filter.
Thanks to Water Softener Authority for additional information.