MSR Sweetwater Microfilter System Review 2016/06/15
Water purification involves everything from local geography and
geology – why is there water flowing here and not over there? In this
review we will look at the MSR Sweetwater Microfilter.
Introduction
There is a lot going on with water. It draws upon biology – what can
harm me in this water? From a survival point of view – how much water do
I need to stay alive? The practicalities – what system is most
appropriate for my specific trip? Point of collection – where is the
best place to collect water from the wild? If you are unsure about the
answers for the questions above, then do some research! You should not
rely completely on one piece of equipment as it is not a substitute for
good outdoor common sense.
MSR Sweetwater Microfilter
This review will deal with the MSR Sweetwater Purifier System which is
part mechanical filter and part chemical solution. The mechanical filter
will deal with most nasties and the chemical solution can be added to
the filtered water to kill off anything left. The construction of the
MSR Sweetwater Purifier strikes a good balance between durability and
weight. At 397g the MSR Sweetwater took some beatings in the bottom on
my rucksack and survived just fine. Of course some general care should
be given to the item as it does contain moving parts along with the
adjustable handle you see in the photo below.
Pre-Filter
The pre-filter is very well constructed and seems very strong indeed,
especially good if used in high flow rivers which may knock it around
against rocks. The float foam stops the pre filter touching the sediment
bottom of the river or stream you are using. Included are several
adapters to fit onto bottles, the ever popular Nalgene wide mouth is
well served here and it fits directly on to a MSR Dromlite or using the
tube straight into a wide mouth Nalgene bottle.
Use
Once you have set the filter up a couple of times it becomes very quick
to do, so with the pre-filter submerged and the float helping keep it
from touching the bottom you can begin to pump. It takes roughly 75
pumps to get a litre (roughly a minute) and the pumping action is smooth
and easy to do. Once you have your water simply disconnect the out tube
and lift the pre-filter out of the water source. Now pump again to
get rid of the water held within the filter, this is very important so
do this each time you have finished collecting water as helps maintain
the filter whilst on the trail and stops it leaking out in your pack.
As I mentioned earlier the MSR
Sweetwater Microfilter is part mechanical and part chemical. The
mechanical section (the filter itself) uses a tiny pore size
(0.2micron) and activated carbon core to clean your water of bacteria,
protozoa, parasites, physical particulate. The MSR Sweetwater is a
microfilter and so only filters the water of large nasties and at the
end of the day unless you add some Purifier Solution you are solely
relying on the filter itself to keep your water clean. The filter is
made of ceramic and can be field maintained using a supplied brush.
Out and About
When travelling in the backcountry your health becomes even more
important. If you contract an infection or virus it could mean you have
to abandon everything and head home. Worst still an emergency situation
occurs where things may get interesting! So its always important to
think about where the water your drinking is coming from and if its safe
to drink. Its also important to consider on longer trips what chemicals
you are consuming to make the water safe. Consequently what these are
doing to your health. Ingesting chlorine, chlorine dioxide, iodine or
indeed any form of chemical based water purification is not ideal for
one's long term health especially if the trip is longer than 3 weeks
which is generally the length of advised use for these chemicals. If you
are using chemicals then please read the suggested use lengths.
Personally I prefer to use the very good mechanical filter of the MSR
Sweetwater Microfilter and then boil the water if I am concerned there
is something in the water. One of my canoe expeditions involved
travelling in areas where you could drink straight from the lakes and
rivers. I wish I would have had the MSR Sweetwater Microfilter then as
it would have added an extra reassurance that was not chemical based.
Viruses
These are incredibly small and can slip through the (0.2micron) pores of
the MSR Sweetwater. If you are in an area with a known problem, then
adding the Purifier Solution will kill them. The solution is made of
Sodium Hypochlorite which is a form of bleach or disinfectant. Commonly
used but has a wide range of completely unexplored side affects and long
term use health issues.
Maintenance
The MSR Sweetwater Microfilter is sadly not field maintainable. The
filter is within its plastic housing and cannot be removed. MSR do
supply a brush for cleaning the inside if it becomes clogged (which it
will through normal use) I would certainly take this on longer trips.
The Silica Depth filter used in the MSR Sweetwater holds a lot of
sediment before becoming clogged which is virtue of this style of filter
medium. The MSR Sweetwater tells the user when the filter becomes
clogged. An excellent feature as it prevents pressure damage in the
filter. Its called the PRV – Pressure Relief Valve and spurts out water
when the pressure gets too high within the filter which is a sure sign
of clogging.
Conclusion
Overall I prefer using mechanical methods of filtration over chemical.
The MSR Sweetwater would work well with boiling in areas of known virus
problems. It would do away the need to use the chemical. Having the
equipment to make fire and a suitable container to boil water in
are in my mind essential items to be carried into the backcountry. The
MSR Sweetwater does have the chance of breaking and so being covered by
a plan b makes common sense. The MSR Sweetwater Microfilter is a
reasonably inexpensive filter. I would take it to areas where I am
reasonably sure the water is ok to drink as passing water through a
filter makes it way easier to deal with rather than using complicated
fabric pre filters which take a long while to work (such as a mil bank
bag). The price of the item makes it very good value in my mind. I will
be using it on future trips. During a week in the Scottish Highlands it
worked fine without the use of the Solution and I did not get ill. When
returning home make sure you dry out the filter completely before
storage.
