HydroBlu Versa Flow Lightweight Water Filter

What it removes from water, and how well that is proved. 6: A bit better than average.

0.1 µm hollow-fibre membrane. HydroBlu says it removes 99.9999% of bacteria and 99.99% of protozoa (the manual says 99.9% of protozoa; we use the page, and the band is the same either way). It names no test standard and links no lab report, so this is bacteria and protozoa claimed with no published test: 3. It does not remove viruses, and the manual says it does not remove particles under 0.1 µm. The UK shop's copy says it 'exceeds EPA standards' and gives 0.02 µm and virus removal; HydroBlu's own pages say none of that, so we ignore it.

How fast clean water comes through when it is new. Real flow drops as it clogs: see Ease of use. 3: Below average. Fine for some trips, not others.

HydroBlu's page says up to 1 US gallon (3.8 L) in 5 minutes (about 0.76 L/min); its manual says about 1 L/min. We band the lower figure, 0.76 L/min, in the 0.6–1.19 band (1 L/min is the same band). Section Hiker puts it at 1 to 1.5 L/min squeezed, and Backcountry Exposure timed a gravity-fed litre at 8 min 13 s, close to a Sawyer Squeeze.

How much it adds to your pack. 10: The best you can buy for this.

57 g for the filter alone (HydroBlu gives the weight in US units on both the page and the manual, which comes to about 57 g); the UK shop lists 54 g. Under the 90 g line. You also need a 28 mm bottle or bag to filter into, which the standalone filter does not include.

Filling, squeezing or pumping effort, how fast it clogs in peaty or silty water, and how easy it is to clean. 8: Clearly better than most.

Reviewers like how simple it is: threaded at both ends so it fits 28 mm bottles and soft reservoirs, it backflushes with a bottle and no syringe, the end caps stop leaks in a pack, and a clear window shows when it needs cleaning (Section Hiker, who swapped his Sawyer Squeeze for it; Backcountry Exposure, who made it his main filter for a season). Both mention a drawback: it leaks with some bottles (Smartwater, which HydroBlu says it does not fit) and Backcountry Exposure had to wind it on very tight, which made it hard to undo. DMS Adventures found it much like a Sawyer Squeeze in use. These reviews date from 2019 and 2020, after the clear window was added; none is from the last few years.

Reviewers disagree on this.