Owner Review - MSR MiniWorks EX Filter

Greg Mehojah

November 29, 2005

 

Biographical Information:

 

Name:              Greg Mehojah

Age:                 33

Gender:            Male

Height:              6’ 1” (1.85 m)

Weight:             210 lb (95 kg)

Email:               gmehojah3@comcast.net

City, State, Country:     Albuquerque, New Mexico

 

Backpacking Background:       

 

I began backpacking this year to reintroduce myself to the outdoors, and introduce my 10 year old son to backpacking.  My trips are typically 1-2 nights with my son and 2 nights when I solo.  My first season has taken me through desert terrain and high-altitude meadowlands throughout New Mexico, as well as day hikes of the foothills and ridgeline trails of the Sandia Mountains in Albuquerque.  I tend to carry most of the gear when I hike with my son, so I am not a lightweight hiker, but plan on moving that direction as my son gets older.

 

Product Information:

 

Manufacturer:               MSR (Mountain Safety Research)

Year of Manufacture:    2005

URL:                            http://www.msr.com/

Listed Weight:               14.6 ounces

Weight as Purchased:    14.8 ounces

Filter Typ:                     Mechanical - Ceramic/Carbon Core

Available Colors:          Red/Gray Clear Plastic (2005 Model)

MSRP:                         $79.95 US

 

The MSR MiniWorks EX is a mechanical water filter that uses a field serviceable ceramic filter with a carbon core.  The ceramic medium is stated to remove bacteria and protozoa including giardia and cryptosporidia, while the carbon core removes odor and taste compounds.  Taste and odor is less important to me than cleaning the water of harmful bacteria and protozoa, but it is nonetheless a nice benefit.  My Miniworks EX came in a brown cardboard box that included the filter, filter housing, intake hose, small green scrub pad for cleaning the filter, and a mesh carry sack, as well as complete user instructions.  There is no outlet hose included for the clean water because the Miniworks EX is designed to screw onto 1 L (1 qt) Nalgene bottles and MSR Dromedary water bags, though I found you can also connect CamelBak bladders to the clean water outlet nipple.  The 2005 model MiniWorks has a red clear plastic pump housing and a gray clear plastic filter housing.  Previous years models used green and blue clear plastic for the pump housing.

 

The MSR MiniWorks EX is a field serviceable filter, meaning you can clean the filter element repeatedly in the field when it becomes clogged from dirty water.  Finally, the intake hose uses a foam pre-filter to prevent the filter from ingesting large particulate, and a foam float to keep the hose from sinking to the bottom of the water source. 

 

Field Use:

 

I bought this filter after researching other filters and asking advice from backpackers locally and on various Internet backpacking related forums.  I knew that I wanted a reliable and easy to use filter for use on backpacking trips with my son.  Field serviceability and the Nalgene compatibility were definitely selling points for me.  Because I was new to backpacking and using a water filter, I decided to try the filter at home first before venturing into the backcountry.  Using the filter is very straightforward.  Simply attach the intake hose and place it into the water source, screw the MinWorks EX to a Nalgene container (both 1 L (1 qt) bottles and Nalgene canteens are compatible)), and begin pumping the handle.  Water is drawn into the pump housing, and pressure fed into the filter housing.  Constant water pressure in the filter housing appears to provide a continuous flow of clean, filtered water.  MSR warns that a new filter cartridge will spit out small bits of carbon with the first few liters of filtered water.  I found this to be true, but it was a minimal amount of material.

 

I also took this opportunity to learn how to disassemble and clean the MiniWorks EX prior to using the filter in the backcountry.  To clean the filter, the user simply unscrews the pump housing from the filter housing, removes the filter element and scrubs the surface clean with the provided green scrub pad.  Scrubbing the surface of the filter element exposes new, clean ceramic material.  Finally, rinse the filter element with a bit of clean water and then reassemble the filter.  The MiniWorks EX comes with a bottom screw-on cap to keep the clean water output clean.  Prolonged use and cleaning will begin to thin the ceramic element, which is why MSR also includes a filter gauge for use in determining when the filter needs to be replaced.

 

Comfortable with use of the filter at home, I headed into the backcountry of Bandelier National Monument with the MiniWorks EX.  This was my first backpacking trip, but I was accompanied by a friend who has backpacking experience in New Mexico.  I had meticulously planned our route so that we would be near reliable water sources (i.e. running streams).  However, we got a late start, and did not reach our intended destination on the first night.  After making camp, I hiked into the nearest canyon to look for water.  I was only able to find a pool of water from a flood event that had clearly been stagnant for some time.  With no other choice for a water source, I began filtering water, but had to clean the filter after filling only one 1 L (1 qt) Nalgene container.  I filtered three liters of water from that pool, cleaning the filter after each one, and headed back to camp.  My hiking partner looked at me and the water skeptically but we were thirsty so we drank our fill.  Surprisingly, the water tasted pretty good.    The next morning we continued on, filtering water from various sources including clear, running streams.  Filtering from clear streams required that I clean the filter element after filtering three liters (quarts) of water.  We continued to use the filter over the course of the three days in Bandelier, filtering 4 to 6 liters (4 to 6 quarts) per day with no problems.

 

I have used the MiniWorks EX on every backpacking trip this season, including some dayhikes where I knew there would be reliable water sources so that I did not have to carry more water than necessary.  I have filtered roughly 200 liters (200 quarts) of water with the Miniworks EX to date, and have not had any intestinal distress as a result, nor am I near needing to replace the ceramic element.  Though we had to clean the filter often, my son and I were able to filter water from a small stream after a herd of cows trampled through by first drawing water off into a large container and waiting for it to settle.  My 10 year old son really enjoys filtering water with the MiniWorks EX, and because the pumping action required is not very difficult, he does it quite often.

 

The only concern with this filter that I had was using it in below-freezing temperatures.  I had heard that if the filter was wet and exposed to freezing temperatures, the ceramic element could crack.  In order to prevent this, I pump air through the filter for one to two minutes, remove the ceramic element, and place it in a baggie to be kept in my sleeping bag at night.  Using this method, I have never had any problems with the element cracking.

 

Summary:

 

I am very pleased with this filter.  The filter is durable, provides clean drinking water quickly and has proved to be very reliable.  Chemical treatment may be a lighter weight alternative to mechanical filtering, but I will happily bear the additional weight and continue to use my MiniWorks EX.

 

Things I like:

 

1.         Field cleanable.

2.         Compatible with Nalgene water bottles and canteens.

3.         Long ceramic element filter life.

 

Things I did Not Like:

 

1.         At 15 ounces, its pretty heavy.

2.         Possibility of ceramic element cracking if frozen.

3.         Replaceable filter cartridge pricey.