Katadyn Micropur MP1 review: purifier tablets that cover the virus gap filters leave

This is a research-based review, based on manufacturer specs and published data. We do not test products. Specs come from Katadyn's product page for Micropur MP1 (20 tablets), checked November 1, 2026, and the product's EPA-registered label. Treatment guidance comes from the CDC.

Filters like the Sawyer Squeeze and Platypus GravityWorks remove bacteria and protozoa but not viruses. Boiling handles everything, but it takes fuel, and in a long outage fuel is the scarcest thing in the house. Chemical disinfection fills the gap. Plain household bleach works against bacteria and viruses, and the CDC gives the dose. Micropur MP1 tablets add two things bleach does not: a sealed, measured dose that stays good for years in a go-bag, and a label claim against Cryptosporidium and Giardia cysts.

The label calls them water purifier tablets for emergency disinfection of drinking water. Each foil-sealed tablet goes into one liter of water, and after four hours the water is ready to drink.

Who should buy it

• Households with a filter who want a virus step that does not depend on fuel.
• Go-bags and car kits, where a 20-tablet strip weighs next to nothing and lasts 5 years from manufacture.
• Anyone storing water long-term who wants a way to re-treat a container that may have gone stale.

Who should skip it

• Anyone who needs safe water quickly. Four hours per batch means planning a day ahead.
• Households planning to treat all their water with tablets. At 1 tablet per liter, a family of four at 1 gallon per person per day uses about 15 tablets a day, by our arithmetic.
• Treating murky water as-is. Katadyn says to use it with tap or clear water, so settle and filter first.

Strengths

• Covers viruses. The EPA-registered label lists viruses, bacteria and cysts. That closes the gap left by hollow-fiber filters.
• Covers Cryptosporidium on the label. Bleach and iodine are weaker against parasites; the CDC calls chlorine dioxide somewhat effective against Cryptosporidium, and the MP1 label lists it with the 4-hour contact time.
• Long shelf life. 5 years from date of manufacture, per Katadyn, in individually sealed foil.
• No fuel and no power. It works in any clear container you can keep dark for four hours.
• Light. The 20-tablet pack weighs about 0.35 oz per its label.

Drawbacks

• Slow. The label requires a 4-hour treatment time for effectiveness.
• Low volume per pack. 20 tablets treat 20 liters, about 5.3 gallons.
• Clear water only. Katadyn specifies tap or clear water, so turbid sources need settling and filtering first.
• Handle with care. The label carries a DANGER signal word: corrosive, causes irreversible eye damage and skin burns. Keep it away from children.
• Fiddly packaging. The label says to open each foil with a knife or scissors and drop the tablet in quickly.

How it compares

Most households need one tool for volume and one for viruses. These three cover the range.

Using it in a long outage

How to use the tablets

1. 01Start with the clearest water you have. Settle it, then run it through a filter if it is not clear.
2. 02Measure 1 liter (1 quart) into a clean container. A dark bottle works best, because the label says to let it react in an opaque container or in the dark.
3. 03Cut open one foil with scissors and drop the tablet in right away.
4. 04Cap it and wait 4 hours. Label the container with the time.
5. 05Drink or cook with it after the 4 hours. Treat the next day's water the evening before.

Building a household treatment plan

For bulk water, the cheapest disinfectant is unscented household bleach: the CDC dose is 8 drops per gallon of clear water (16 if cloudy), with a 30-minute wait. Keep tablets for the go-bag, for travel to a shelter, and for water you plan to store and drink later. A practical setup is a gravity filter for volume, bleach for daily disinfection, and a strip of Micropur in every bag.

Tablets do not remove chemicals. Water that may contain fuel or floodwater runoff is not made safe by any tablet or filter; use stored water and follow local notices. See our guide to water when the taps stop for how long municipal systems keep running.