I have a Sweetwater Guardian, and I like it. It’s probably easier to pump than any other filter because of the lever it uses. I do know (from using at REI) that it pumps easier than an MSR filter with a similar lever. However, if I were buying a filter for the first time, I would consider an MSR Miniworks or Waterworks or a Katadyn Pocket Filter or Minifilter. The MSR filters attach directly to a water bottle (or my MSR Dromedary water bag), so there’s no output hose to get contaminated. The Katadyn filters seem to get the most use out of their replaceable filter elements, if their claims as to filter life are accurate. All of those filters have the requisite pore size (.2 microns, I believe) to filter out cysts, protozoa, and most bacteria. In any case, check out the monthly panel here about water filters and contaminants, or go to rei.com and find their chart that compares the abilities of various makes and models of filters, to make sure the one you buy removes the things from the water that you want it to. And remember this is only one opinion (mine) among many. You may place greater emphasis on other factors in choosing a water filter. A trick to extend the life of any water filter, which I probably read in this newsgroup, is to cover the “prefilter” at the end of the intake hose that goes into the water source with a coffee filter, to strain out the larger contaminants and keep them from clogging the filter element.
We have a Pur water purifier which needs a replacement filter every so often. When we recently went to our local camping store, where the purifier was bought, to buy a new filter, we were told they are no longer allowed to sell these. There are plenty of stocks we were told, but they are not allowed to sell them, or the purifiers. However they cannot or will not say why, or whether this is a permanent or temporary state of affairs. They also refused to tell us how or where to contact the makers of the product! They say a similar ban applies to the Sweetwater brand purifier. Does anyone know anything about why the purifier & filter are banned, &/or where to contact the manufacturer, or any other relevant information? First, understand that there is a difference between a FILTER and a PURIFIER. The former filters out bacteria and protozoa but not viruses. The latter filters out bacteria and protozoa and kills the viruses chemically. (OK, the latter may also kill any remnant bacteria and protozoa as well.)
I’m off to Nepal to do some trekking soon and considering taking a water purifier with me mainly to ensure a safe supply of drinking water but also to do my bit at reducing the plastic bottle pollution epidemic. Can anyone recommend a good purifier that’s both compact and capable of producing enough clean water for two people for the duration of the Annapurna Circuit trek I’m reckoning on about a liter each a day for twenty one days. All I can say is, make sure you have some iodine tablets (and something to kill the taste) because you never know when the darn machine’s going to break.
We have a Pur water purifier which needs a replacement filter every so often. When we recently went to our local camping store, where the purifier was bought, to buy a new filter, we were told they are no longer allowed to sell these. There are plenty of stocks we were told, but they are not allowed to sell them, or the purifiers. However they cannot or will not say why, or whether this is a permanent or temporary state of affairs. They also refused to tell us how or where to contact the makers of the product! They say a similar ban applies to the Sweetwater brand purifier. Does anyone know anything about why the purifier & filter are banned, &/or where to contact the manufacturer, or any other relevant information?
I have a Pur Scout water purifier.
I am no expert on the ultraviolet method of water purification, but have never heard about the cancer causing aspects of it. I tend to ignore a lot There are none, as it’s the UV that causes (skin) cancer. If the unit is competantly installed (a blueish glow visible anywhere is bad news) there should not be any risk. There is certainly no risk when it comes out of the taps. The way to rate UV systems is how long the water is exposed to the UV, and how intense it is. This is measured in units like s * mw/cm^2. Exposing stuff to UV for ten times as long is as good as ten times the power for a tenth of the time. Various stuff requires different amounts of UV to kill it. The hardest stuff to kill is generally spores. The UV generated by your water purification unit is what’s called short wavelength or germicidal UV and it’s very fast and effective at killing viruses, bacteria and other nasties. If the unit is sized for your water system and operating properly, it will work and the manufacturer’s literature or web site should tell you if you have the right unit for your application. To be absolutely sure, sample the incoming and output water and have it tested. Short wavelength UV can damage skin and eyes so you should not expose yourself to UV radiation from the lamp.
A water purifier is very different from a water filter. Figure out what you need. A purifier may be a desalinizer, such as a reverse osmosis membrane that removes salt from sea water. these will be more expensize to buy and keep up (replace membrane cartridges).
Agreed with all the statements in your post, so I have nothing to come back with, Your definately right about pure water being a magnet for impurities! Even 2 megohm water sucks ammonia right out of the air and it becomes useless even for simple lab tests. I just had notorious luck with 4 out of 4 very expensive powered RO systems, the membranes continually clogged, no matter what steps I went through to protect them and keep them clean. As far as DI, it is much easier to recharge a DI setup every 3 months, than to clean the RO every week and still have to replace the membranes. Provided the DI is set up in a manner that makes recharging simple and efficient.
