Katadyn
Katadyn Explorer Pro Purifier
- Protection: 6/10 What it removes from water, and how well that is proved.
- Flow rate: 4/10 How fast clean water comes through when it is new. Real flow drops as it clogs: see Ease of use.
- Weight: 1/10 How much it adds to your pack.
- Ease of use: 5/10 Filling, squeezing or pumping effort, how fast it clogs in peaty or silty water, and how easy it is to clean.
Trips abroad and expeditions where viruses are a risk
- Type
- Pump
- Removes viruses
- Yes
- Flow
- 1 L/min
- Weight
- 630 g
- Pore size
- 0.01 µm
- Rated life
- 10000 L
Where to buy
Alpinetrek £408.45 In stock. Free delivery. Free UK delivery from £85.
View at shop: AlpinetrekHeinnie £459.99 In stock. Free delivery. Lists the weight as 630 g. Free UK delivery over £50.
View at shop: HeinnieUltralight Outdoor Gear £469.99 Out of stock. Shown with an RRP of £499.99. Free tracked UK delivery. Lists the weight as 691 g.
View at shop: Ultralight Outdoor GearPrices checked 8 Nov 2026 on each shop's own page; shops can change them. We earn no commission on these links; shops are listed by price. More
Our ratings (out of 10)
1 to 10, compared with the whole market. Each says what it's based on. How we score
Protection
From maker's figures 6/10What it removes from water, and how well that is proved. 6: A bit better than average.
Three stages: a 0.2 µm ceramic cartridge (bacteria, protozoa), activated carbon, and a 0.01 µm hollow-fibre virus membrane (Katadyn fact sheet). Katadyn's manual claims reductions of 99.9999% for bacteria, 99.9% for protozoan cysts and, with the virus stage fitted, 99.99% for viruses. The only tests it lists are two by Bachema AG on E. coli and Pseudomonas aeruginosa (bacteria), with no results published and none listed for protozoa or viruses, and it names no standard such as NSF or EPA. So bacteria and protozoa are claimed without a published test: 3, not the 4 for a named standard or published lab report. A named standard for all three would make it a 5. Virus protection needs the virus stage fitted. GearJunkie lists the virus membrane as 0.1 µm; Katadyn's fact sheet says 0.01 µm.
Flow rate
From maker's figures 4/10How fast clean water comes through when it is new. Real flow drops as it clogs: see Ease of use. 4: A bit below average.
Katadyn gives up to 1 L/min depending on water quality, in the 0.6–1.19 L/min band. GearJunkie found it slower: 2.5 minutes to fill a 1.4 L bottle with the microfilter alone, and 3 minutes with the virus stage fitted (about 0.5 L/min). Banded on Katadyn's figure.
Weight
From maker's figures 1/10How much it adds to your pack. 1: A real weak point.
630 g (Katadyn), in the 450 g and over band. Ultralight Outdoor Gear lists 691 g.
Ease of use
Estimate from maker's specs: filter type 5/10Filling, squeezing or pumping effort, how fast it clogs in peaty or silty water, and how easy it is to clean. 5: Does the job. Average for wild-camping gear.
Estimate from maker's specs
In short
Good for
- Trips abroad and expeditions where viruses are a risk
- Groups of 2 to 5 (Katadyn's group size) who treat water for several people
- Cloudy or silty water: the ceramic stage protects the virus membrane
- Using as a plain filter at home in the UK, with the virus stage left off to save weight
Strengths
- Removes viruses as well as bacteria and protozoa when the 0.01 µm virus stage is fitted (Katadyn)
- Modular: the carbon and virus stages can be left off for trips that don't need them
- Ceramic can be cleaned, and all three stages store dry between trips (Katadyn)
- Ceramic rated to 20,000 L, virus membrane to 10,000 L, carbon to 500 L (Katadyn)
- Steel pump piston and an overpressure valve (Katadyn)
- Carbon stage improves taste (Katadyn; GearJunkie found the water clean-tasting)
Weaknesses
- 630 g, heavy for solo trips (Katadyn; GearJunkie)
- Katadyn gives up to 1 L/min, but GearJunkie measured about 0.5 L/min with the virus stage fitted
- No named standard or published test report behind the claims, and no test listed for protozoa or viruses
- With the virus stage fitted the bottle can't screw on: a second tube is needed, the bottle sits open and the hoses are short (GearJunkie)
- Carbon stage lasts only about 500 L (Katadyn)
- Katadyn's manual says not to let the virus membrane freeze and to check the ceramic for cracks after freezing; it does not say the filter is safe to use after freezing
- New in 2026: no long-term durability reports yet
Sources
We haven't tested this ourselves. Every score comes from these specs, tests and reviews.