LifeStraw Peak Series Compact Gravity Water Filter System 3L

What it removes from water, and how well that is proved. 8: Clearly better than most.

Bacteria and parasites at 0.2 µm, to NSF/ANSI P231 with an outside lab report (LifeStraw). A named standard for bacteria and protozoa, so 4. No virus claim.

How fast clean water comes through when it is new. Real flow drops as it clogs: see Ease of use. 6: A bit better than average.

LifeStraw's page gives 1.7 L/min for this system (new filter). 1.2 to 1.79 L/min. LifeStraw's own longevity test for the Peak Gravity (size not stated) found about 1.55 L/min new, falling to about 0.57 L/min at 2,000 L. OutdoorGearLab timed 30 to 90 seconds a litre (0.7 to 2 L/min) depending on how high the bag hangs, and 30 to 35 seconds when it is hung well and the filter is clean.

How much it adds to your pack. 5: Does the job. Average for wild-camping gear.

228 g for bag, hose and filter (LifeStraw's page). 150 to 299 g. OutdoorGearLab measured 230 g. You also carry a vessel to drink from.

Filling, squeezing or pumping effort, how fast it clogs in peaty or silty water, and how easy it is to clean. 7: Better than most.

Fill the bag, hang it and walk away: no squeezing or pumping. GearJunkie (4) used it daily on an Appalachian Trail thru-hike and liked cooking while it filtered. Expedition Portal (4) found it easier than a pump but hard to fill from shallow pools, so it carries a bottle for scooping. We Are Explorers (4) found setup simple apart from a fiddly hose fit. OutdoorGearLab (3) also found it hard to fill in shallow water and says there is no separate clean-water vessel. Average 3.8 out of 5, so 7 out of 10. OutdoorGearLab's 10-point scores are halved and a half rounds down (9.0 becomes 4, 8.0 becomes 4, 7.0 becomes 3, 5.0 becomes 2), the same as on other Fellkit pages.