Katadyn Vario Water Filter

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

Katadyn says the glass-fibre cartridge removes bacteria, protozoa, cysts and sediment. Its manual says it meets industry standards for 99.9999% of Klebsiella terrigena and 99.9% of Giardia and Cryptosporidium, and was tested at 2,000 litres. It names neither the standard nor a lab and publishes no report, so this is a claim with no published test: 3 (not the 4 for a named standard or lab report). Katadyn publishes no pore size for the cartridge (UK shops give 0.2 or 0.3 µm; the ceramic prefilter disc is 1.0 µm). It does not remove viruses, and OutdoorGearLab suggests backup chemicals if viruses are a worry.

How fast clean water comes through when it is new. Real flow drops as it clogs: see Ease of use. 7: Better than most.

Katadyn gives up to 2 L/min in Faster Flow mode (ceramic prefilter bypassed) and about 1 L/min in Longer Life mode, in the 1.8–2.49 L/min band. OutdoorGearLab timed 39 seconds a litre in Faster Flow and 47 seconds a litre in Longer Life (about 1.5 and 1.3 L/min), the second fastest pump in its test. Banded on Katadyn's figure.

How much it adds to your pack. 3: Below average. Fine for some trips, not others.

425 g (Katadyn), in the 300–449 g band. OutdoorGearLab weighed 550 g and called it the second heaviest filter in its test; Ultralight Outdoor Gear lists 434 g.

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.

OutdoorGearLab (4) found it smooth and easy to pump with the best handle of the pumps it tested, but it has many parts and takes a read of the manual to set up. World's Greatest Dad (4) filled a wide-mouth bottle in about 30 seconds, with the bottle screwed straight on. Alaskan Ballistics (4) found it pumped quickly and recommended it, with a slightly fiddly set-up. Hunt & Honey Homestead (4) found it smoother and easier than the Hiker Pro, with the bottle thread built in, but says some people have trouble priming it. Follow The Compass North (3) says muddy water means scrubbing the ceramic every 5 to 10 litres or the pump gets hard. Average 3.8 out of 5, so 8 out of 10.