Hikers and campers have learned that it is easier and more convenient to carry a portable water filter than it is to carry a lot of heavy bottles of water. Having enough clean, pure water while hiking or camping is an important health consideration and filling up buckets from a nearby lake or stream may not be the safest way to supply the needs. Regardless of how clean the water may appear, it should be filtered before drinking if not boiled to kill any disease-causing bacteria floating around in the water.

Staying hydrated is also an important need for those on extended bicycle rides and carrying a gallon or two on a bike can be troublesome. Having a portable water filter is the best thing a bicycle rider can do to make sure they always have access to a fresh water supply. Whether it is a filtering system built into their water bottle or a separate system through which water from a stream or lake can be processed, making sure they do not become ill from the water is a priority.

Ionic Absorption is one method many companies use to purify water. Electrolysis is another and small water bottles with a purification system built into the tops are popular among many of those who love the outdoors. However, a berkey water filter is also beneficial in that filtered water is easier to purify and removes most of the suspended particles before the water goes through the purifier.

A portable water filter may include a pitcher with a filtering system in place. Simply add water to the pitcher and the filter can remove many of the contaminants from the water as it passes through the filter. Water that is heavily laden with bacteria still may not be safe to drink if the filtration of the water is so large it allows the bacteria to pass through.

Most bacteria that threaten water supplies is larger than one micron and a portable water filter that filters to that size will generally remove all bacteria from the water. Generally, the more effective portable water filters, such as the Big Berkey and Crown Berkey, are gravity-fed so that the bacteria and sediment are not forced through the filter by water pressure. This process of slowing the flow rate or time of exposure through the filter has been calculated to yield the greatest volume removal of toxic chemicals caused by pollution from industry and agriculture.

Although water can be filtered to remove all bacteria and sediment, not all odors will be eliminated, regardless of the quality or cost of a portable water filter. Water in this condition will require special treatment that filtering and purification help.