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.
: For my trip I will be boiling water primarily, the Winipeg River in the area
: we are paddleing is flowing through precambrian shield so there is very
: little silt, and fires are allowed unless things get very dry in the next
: 2 weeks. I would still like to get a filter for backpacking and for trips
: in areas where the water is less pure.
: Ken
