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Choose a water-treatment method by checking the organisms it can remove or kill, the clarity of the water, and how much water you need to treat. A filter’s label matters more than the word “filter”: most portable filters do not remove viruses. If virus protection is needed, boil the water or filter it and then disinfect it according to the product directions.
Start with the water source and the risk
Clear-looking stream or lake water can still contain germs. Treat water of uncertain safety before drinking it, using it to cook, brushing your teeth, or preparing food. The Centers for Disease Control and Prevention (CDC) advises hikers and campers to choose treatment based on the contaminants they need to address, not on appearance alone.
Germ treatment is not the same as chemical cleanup. Water suspected of containing fuel, toxic chemicals, or radioactive materials cannot be made safe by boiling or disinfecting. Use bottled water or another source and follow local health guidance.
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Check the exact pore-size or certification claim
For parasite removal, CDC guidance says to choose a filter with an absolute pore size of 1 micron or smaller, or one certified to NSF 53 or NSF 58 for cyst reduction or removal. For bacteria as well as parasites, CDC identifies an absolute pore size of 0.3 micron or smaller. These thresholds do not mean the filter removes viruses.
#1 Best Overall
- Removes Bacteria & Parasites: The Microfiltration Membrane Removes 99.999999% of Waterborne Bacteria (Including E. Coli and Salmonella), and 99.999% of Waterborne Parasites (Including Giardia and Cryptosporidium) - Essential for Your Survival Kit
- Removes Microplastics: Removes the Smallest Microplastics Found in the Environment (Down to 1 Micron), and Reduces Turbidity Down to 0.2 Microns - Ideal for Hiking and Camping Essentials
- Rigorous Testing: All Claims Are Verified with Laboratories Using Standard Testing Protocols Set by the US EPA, NSF, ASTM for Water Purifiers
- Long Lifetime: The Microbiological Purification System Will Provide 4,000 Liters (1,000 Gallons) of Clean and Safe Drinking Water - a Must-Have for Your Bug Out Bag
- Make an Impact: For Every LifeStraw Product Purchased, a School Child in Need Receives Safe Drinking Water for an Entire School Year. Essential Camping Accessory Made With BPA Free Materials
Read the documentation for the exact model you plan to carry. Do not assume that “filter” or “purifier” guarantees a particular level of protection; look for the stated pore size or a relevant certification and match it to the organisms the product claims to address. CDC’s thresholds and advice are in its outdoor water-treatment guidance.
Account for viruses separately
Most portable filters do not remove viruses. If viruses may be present, use a treatment method that addresses them: boil the water, use an appropriate disinfectant after filtering, or use a portable UV device as directed. Filtering before disinfection is a practical option when boiling is unavailable; effectiveness varies by organism and product, so follow the label’s dose and contact time. CDC notes that some disinfectants are less effective against parasites; chlorine dioxide has some effectiveness against Cryptosporidium, but filtering first remains the safer approach.
Rank #2
- CLEAN WATER ANYWHERE: Our water filter straws solve the real challenge of being on the move, finding water is rarely the problem, finding water that's safe to drink is. Each filter removes over 99.99% of waterborne bacteria and parasites so you stay properly hydrated and in the best shape possible
- LIGHTWEIGHT & PORTABLE: Our filters weigh only 2 oz and measure 8 inches long, so you can take them with you anywhere. Be prepared when camping, hiking, enjoying the outdoors, or when facing unexpected situations such as natural disasters, accidents, or just about anything
- HIGH LEVEL FILTRATION: Each of the 5 filters removes over 99.99% of waterborne bacteria (such as E. coli and Legionella) and over 99.99% of waterborne parasites (such as Giardia and Cryptosporidium), including the smallest microplastics found in the environment, down to 0.1 micron
- LASTS UP TO 10 YEARS: Each filter reaches up to 1800 gallons, providing up to 10 years of drinking water for the average person. Built BPA-free, FDA-compliant, manufactured under rigorous quality control standards and tested regularly for performance, individually sealed with its own backflushing plunger
- EMERGENCY PREPAREDNESS: Keep this lightweight filter when backpacking, fishing, hiking, camping, hunting, or exploring the wilderness. Perfect for power outages, hurricanes, earthquakes, floods, and storms. Keep a set in your car or bugout bag, so you're always prepared wherever life takes you
Compare treatment methods for your trip
| Method | What CDC guidance says it can address | Important condition |
|---|---|---|
| Portable filter | Parasites with an absolute pore size of 1 micron or smaller or NSF 53/58 cyst-reduction/removal certification; bacteria and parasites with an absolute pore size of 0.3 micron or smaller. | Most portable filters do not remove viruses. Verify the exact model’s documentation. |
| Filter, then disinfect | Disinfection can address viruses and bacteria; effectiveness against parasites depends on the method and organism. | Filter first when possible, follow the disinfectant’s directions and contact time, and do not rely on it for chemical contamination. |
| Boiling | CDC calls boiling the best way to kill germs. | For clear water, bring it to a rolling boil for 1 minute, or 3 minutes above 6,500 feet. Let it cool safely; settle or pre-filter cloudy water first. |
| Portable UV | Can kill parasites, bacteria, and viruses in small amounts of clear water. | Cloudy water should be filtered first because particles can shield germs from UV light. |
The boil times are CDC guidance published in 2025 for clear water. Emergency instructions also advise settling or filtering cloudy water before treatment. See CDC’s hiking, camping, and travel guidance and CDC’s emergency water guidance.
Choose for hiking, camping, or an emergency kit
For hiking and camping
- Identify whether your likely water sources call for protection against parasites, bacteria, viruses, or a combination.
- Check the specific filter’s absolute pore size or cyst-reduction/removal certification rather than relying on a generic product description.
- If virus protection matters, bring a compatible disinfection option or plan to boil; account for the water clarity and directions required by the method.
- Consider your practical constraints: how much water you need, whether you can heat it, and whether you can carry and use treatment consumables. These factors help choose a method but do not establish one product’s performance over another.
For an emergency kit
Keep water treatment within a broader safe-water plan. After a disaster, CDC advises using bottled, boiled, or treated water and following health-department recommendations. A filter can help with germs when its claims match the hazard, but it is not a remedy for water contaminated by fuel, toxic chemicals, or radioactive material. Review current instructions for any treatment product you store.
Rank #3
- Drink Anywhere, Certified by Science - This survival-grade straw filter meets strict NSF/ANSI 42, 372, 401 standards (Test Report: NBF21-004693-01). It instantly removes 99.9999% of total coliforms (including E. coli and other representative organisms). It’s designed for extreme reliability during hiking, camping, international travel, or emergency preparedness—proven by science, trusted by adventurers.
- Triple NSF Certified for Complete Reliability & Superior Taste - Breathe easy with every sip. Our straw is independently certified to NSF/42 (for chlorine & taste improvement), NSF/372 (lead-free materials), and NSF/401 (reducing microplastics and particulate). This triple verification guarantees you get the best-tasting water while keeping metals, microplastics and particulate at bay.
- Portable & Long Life-Span - This straw filtration at only 7.1'' long and 1" in diameter fits any 28mm threaded bottle, cup, or glass. It weighs just 2 ounces and fits in the palm of your hand, pocket, gym bag, backpack, survival pack or purse. Both ends of the Upgrade water filter straw are removable for extend Longer Lifespan ensuring it provides up to 1,320 gallons (5,000 liters) of drinking water. Don't miss this opportunity to drink water conveniently wherever you go.
- 5-Stage Filtration - Our Upgrade 5-Stage Filtration System includes a coarse filter screen, double layer pp cotton fiber, coconut shell activated carbon and hollow fiber ultrafiltration membranes. Flexible use of threaded water inlet cap to easy backflush. (IT DOES NOT LOWER TDS VALUE, ensuring water's essential mineral balance remains untouched.)
- 0.1 Micron Pore Size & Balanced Flow Rate - This water filter straw features a 0.1 micron pore size, designed to help improve filtration precision. It delivers a flow rate of up to 16.9 fl oz/min (500 ml/min) for a balance between filtration performance and drinking speed, making it suitable for outdoor, travel, and emergency use.
What to verify before buying a particular model
General CDC guidance does not rank current filter models or establish their flow rates, service life, freezing tolerance, replacement availability, weight, or cost. Check the current documentation for your exact model and intended region for those details, along with the precise organisms and conditions covered by its claims. Do not infer any of them from pore size alone.
Quick Recap
Best Value
- LifeStraw Go Series is the ULTIMATE SIDEKICK. The BPA-Free bottle filters out nasties so you can fill up from airport bathrooms, a tap in Mexico, or a gas station while road-tripping
- IMPROVES TASTE: the Carbon filter reduces chlorine, odors + organic chemical matter
- FILTERS OUT CONTAMINANTS: the Membrane microfilter protects against 99.999999% Bacteria (including E.coli + Salmonella), 99.999% Parasites (including Giardia and Cryptosporidium), 99.999% Microplastics, sand, dirt, and cloudiness
- LONG LASTING: The membrane microfilter lasts up to 1,000 gal (4,000 L) - about five years of daily use. Carbon filter lasts up to 26 gallons (100 L) - about two months
- SAVES WASTE: The membrane microfilter lasts up to 4,000 liters. That’s 8,000 single use plastic water bottles out of our parks, our oceans, and our communities
Rank #4
- Ideal for outdoor recreation, hiking, camping, scouting, domestic or international travel, and emergency preparedness
- High-performance 0.1 micron absolute inline filter fits in the palm of your hand and weighs just 2 ounces; 100% of MINI units individually tested three times to performance standards by Sawyer
- Attaches to included drinking pouch, standard 28 mm disposable water bottles, hydration packs, or use the straw to drink directly from your water source
- Removes 99.99999% of all bacteria (Salmonella, Cholera, and E. coli); removes 99.9999% of all protozoa (such as Giardia and Cryptosporidium); also removes 100% of microplastics
- Filter rated up to 100,000 gallons; Includes one Sawyer MINI filter, 16-ounce reusable squeeze pouch, 7-inch drinking straw, and cleaning plunger.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
