Best Water Filter Made — MSR Guardian Purifier
The MSR Guardian Purifier is unique to the world of pump-based units because of a new kind of “hollow fiber” filter so small it eliminates viruses. Indeed, it is touted to remove 100 percent of every biological threat — viruses, bacteria, and protozoa — from pretty much any water. It also cleans itself, “flushing” the filter cartridge with 10% of the water you pump.
That 10% is dumped out via a waste line, while 90% — the purified water — is collected in your bottle. MSR notes it works for 10,000 liters without maintenance, meaning four people drinking four liters a day (for 60 days a year) can use it for 10 years before you replace the cartridge.
A hard-to-break plastic case is touted to withstand 300 pounds of force. It’s fast too: The Guardian pumps 2.5 liters a minute. Simply awesome. Drawback? The price tag is $350, but it’s no secret, you get what you pay for.