Wink said:
Voivode, the main advantage of UV treatment over pump filters for me would be taste. Many of the manual pump filters contain (or need the addition of) iodine or chlorine to kill viruses which can pass through some filters. The UV method means you get fresh tasting water, and the running costs are minimal. Note to Santa methinks...
Every water purification system has its advantages and disadvantages. This unit is great except for the inability to treat for heavy metals and it will not work in turbid water, requiring some form of filtering step.
Some mechanical systems do use chemicals, but many of the high end ones over here do not. They use a ceramic cylinder with apetures small enough to trap everything except for virii.
Example of an MSR unit
Now, if they water you're treating is dirty enough that you're concerned about a virus, mechanical filtration obviously isn't going to cut it (virus size<<<pore size), and that's when the chemicals or the UV come out.
It's something of a cost/benefit analysis for me. The water here is largely clean except for the potential of bacteria and microorganisms. The mountain water is largely fast-flowing glacial rivers and streams, which can be very cloudy. Virii are not an issue. That makes a mechanical system the best suited for the job out here.
Now, if I were spending time roaming around, say, India or Africa, where the water might be coming from the same hole that the wildebeast are drinking from, I'm going to want more stringent measures. That will probably include pre-filtering and either UV or chemical treatment.
