Mike,
">Hope this helps"
Jeepers, it does more than help. You answered questions that I didn't have enough knowledge to even ask.
Thanks a million for taking the time to reply in such a thorough manner!
Ken
: No worries!
: Well, I've have a Sweetwater Guardian, broke a MSR waterworks, and a Katadyn
: Pocket Pump. I broke a MSR Waterworks probably because every so many of a
: group will break and of course, I have an uncanny skill in choosing the
: flawed. There are others, too.
: My personal choice: Katadyn Pocket Pump. I have had mine for nearly a quarter
: century and have the original filter, too (though it is getting close to
: changing time). http://www.katadyn.net/katadyn_pocket.html
: Pros: it's strong, dependable, filter lasts for at least 18,000 gallons, and
: the parts are available forever. The silver iodide impreganated filter is
: hard and resists bacterial growth. The unit can be field-stripped and
: components are replaceable. Pump pressure is direct action, no level to
: break. Many special forces units worldwide use it, too.
: Cons: initial costs are the highest, it weighs several ounces more then the
: next heavier backpacking water filter. Pump force is direct pressure
: versus lever action and pumping force is higher.
: Performance measures: cost per gallon of water make the filter the cheapest
: unit available. Microfiltering is the best of all portable units
: available.
: Katadyn Mini Ceramic: untested
: http://www.katadyn.net/katadyn_miniceramic.html
: Pros: seems to be light at 8 oz and small, silver iodide treated filter media
: inhibits bacterial growth
: Cons: it has a filter life of 2000 gallons meaning it has a filter element
: like the MSR, a softer media then the Pocket Pump.
: Performance measures: unknown.
: Sweetwater Guardian and components: A lighter pump that uses a lever action
: to reduce pumping force. Cascade Design were the next company to mass
: produce backpacking filters challenging Katadyn. I've used mine all over
: the world.
: http://www.cascadedesigns.com/sweetwater/guardian.asp
: Pros: cheaper then most other filters, pumping force is easier using a lever
: Cons: soft filter media erodes rapidly, bacterial growth in element, filter
: pores are too large and allow for intrusion of filtrate that can't be
: removed easily, filter lasts less then the MSR and substantially less then
: the Pocket Pump. Plastic lever can break under stress.
: Performance measures: filter costs add up rapidly driving up gallon costs
: (treating the filter increases the filter life substantially).
: MSR Waterworks: I broke the lever off while on a backpack trip in the
: Bugaboos. Later on I dropped the filter element and cracked it. The second
: most expensive filter after the Pocket Pump.
: http://www.msrcorp.com/filters/waterworks_ex.asp
: Pros: screw the water bottle to the underside of the pump to ease the
: delicate choir of balancing on the rocks in the creek. The filter lasts a
: little longer then the Sweetwater. Lever action eases pump force.
: Cons: the screw on function leaves a potential cross-contamination pathway.
: The lever can break. Much more expensive then the Sweetwater, approaches
: the cost of the Pocket Pump.
: Performance measures: water filtering costs are high, filter is softer
: ceramic filter then the pocket pump.
: MSR MiniWorks: untested
: http://www.msrcorp.com/filters/miniworks_ex.asp
: Pros: cheaper then the WaterWorks, more expensive then the Sweetwater. Screw
: the water bottle to the underside of the pump to ease the delicate choir
: of balancing on the rocks in the creek. The filter lasts a little longer
: then the Sweetwater. Lever action eases pump force.
: Cons: the screw on function leaves a potential cross-contamination pathway.
: The lever can break. More expensive then the Sweetwater.
: Performance measures: untested.
: A note about filters, microfilters and water purification: The pumps above
: are all microfilters, meaning that they will filter out bacteria and
: protozoa but will not filter out virus at 99.9% efficiency. What this
: means is that some virus will get through and cause illness. For instance,
: Norwalk virus, a common cause of "food poisoning," will get
: through the Sweetwater media and a large portion of which will also make
: it's way through the softer "ceramic" filters. To insure pure
: water, chemical treatment is needed with either chlorine, ammonium
: chloride or iodine with contact time of a few minutes. Boiling for a few
: minutes does the same thing.
: About the carbon and pesticides claims: Much of the pesticides and herbicides
: and chlorinated hydrocarbons aren't caught due to a variety of reasons.
: This is a shortcoming of carbon and just the way it is. Reactivation of
: the carbon by heating drives off the chemicals that are trapped for reuse.
: The more carbon and surface area means beteer capture, but this
: dramatically increases pump force. Integrated carbon filters are
: marginally effective and decrease the filter media for trapping bacteria
: and debris.
: A comparison website with prices can be found here:
: http://www.rei.com/online/store/Search?storeId=8000&query=*&cat=4500461 #
: Click on the Comparison Chart and the Ask the Expert or whatever it's called.
: Hope this helps.
