Water gets pulled through four stages on its way to you. A cotton pre-filter takes the worst of it. A screen catches grit. Activated carbon cuts chlorine and the taste that makes water hard to drink. Then
a 0.1 micron membrane - thousands of tiny straws inside the straw - stops bacteria and protozoa. No power. No pumping. Just sip.
Field Straw FS-1 Personal Water Filter
$39.95
Sale price
$39.95
Regular price
Skip to product information
Field Straw FS-1 Personal Water Filter
- Works when the power grid fails
- Removes 99.999999% of contaminants
- Never expires, backed for life
- Provides up to 400 gallons of clean water
- Scientifically developed & lab-tested
- Ultra-light & portable
Pickup currently not available
60-Day Risk Free Trial
Lifetime Warranty
Fast & Free Shipping
Product description
You go to fill a pot for pasta and the water comes out brown.
Or the boil notice arrives on your phone — hours after you already drank from the tap.
That is not the apocalypse. That is a Tuesday. And it is the reason to own one of these before you need one.
It is not just a straw
You have probably seen the photo: someone lying face-down at a creek, sucking water through a tube. That is the part people complain about, and fairly.
So this one ships with the parts that fix it. The extension hose means you can draw from a bucket or a jug instead of lying in the dirt. The collapsible pouch means you can fill it and carry clean water back with you. You are not stuck at the water source.
How it works
Put the bottom end in the water. Drink from the top. No power, no batteries, no waiting, nothing to charge.
Water passes through four stages on the way to you:
- Cotton pre-filter — catches the big stuff first
- Coarse screen — grit and sediment
- Activated carbon — cuts chlorine, odor and bad taste
- 0.1 micron hollow-fiber membrane — the main event
That last number is the one that matters. Bacteria are bigger than 0.1 micron. So they do not get through. That is the whole idea.
What it does not do
We would rather tell you now than have you find out later.
It does not remove viruses. No straw filter of this type does. Anyone who tells you otherwise is selling you a story.
It does not remove chemicals, lead, or PFAS. Carbon improves taste and cuts chlorine. It is not a chemical treatment. If your water is contaminated with chemicals rather than microbes, this is the wrong tool — and we will tell you that instead of taking your money.
It does not work on saltwater.
For anything the filter cannot handle, boil the water or use purification tablets. The free Field Manual explains exactly when to do which.
Two things that will kill it, and how to avoid them
Most of these get bought, put in a drawer, and forgotten. That is the point of them. But two things can quietly ruin a hollow-fiber filter while it sits, and almost nobody tells you about either.
Storing it wet. A filter put away damp can clog on the shelf. Flush it with the included backwash syringe after each use and let it dry. Two minutes, and it stays ready.
Letting it freeze. If water is left inside and it freezes, the fibers can crack — and it may still look and feel fine afterward. If you keep one in a car through a cold winter, bring it indoors, or keep a spare inside as your reliable one.
In the box
- Field Straw FS-1 filter
- Backwash cleaning syringe
- Extension hose
- Collapsible water pouch
- Carabiner clip
- Instructions
- The free Field Manual, emailed within minutes of ordering
Most people buy more than one
Not because we push it. Because one in the kitchen drawer does not help you in the car. Customers tell us the same thing every time: one per vehicle, one per bag, one for each person at home.
A family of four with two cars is seven straws. They do not expire sitting on a shelf. That is the point of buying once.
Try it for 30 days. If it is not right, send it back for a full refund. No restocking fee, no interrogation.
Shipping Information
We ship across the United States. Free over $75, otherwise a flat $7.45 shown at checkout before you pay.
Most orders arrive 7 to 14 days from the day you order, not from the day it ships. Our gear comes direct from our manufacturing partners, and that is the door-to-door number.
A live tracking link lands the moment it ships. Larger orders may come in more than one package so nothing waits on anything else, each tracked, no extra cost.
Your free Field Manual arrives by email within minutes, so you have the plan long before the box.
How to Use
Three steps. No pump, no batteries, no waiting.
STEP 1
Pull the cap off the top and the cover off the bottom. Keep both. The bottom cover is what keeps grit out of the filter between uses.
STEP 2
Put the bottom end straight into the water. A creek, a rain barrel, the bathtub you filled before the storm. If it's cloudy, let it settle a few minutes and drink from the clear part on top.
STEP 3
The first pull takes some effort while the filter wets through. After that it flows easy. When you're done, blow back through it to clear the fibres, then cap both ends.
WHAT HAPPENS INSIDE THE TUBE
WHAT A FILTER ACTUALLY DOES
Silt and sediment come out on the first pass -that part you can see. The part that matters is invisible: bacteria and protozoa that pass straight through a screen and stop at a 0.1 micron membrane. Clear water is not the same as safe water, which is why the membrane is the stage that counts.
Your Satisfaction. Our Mission.
See what other customers say
Very Good 4.7/5
“I bought this for hiking and emergency preparedness, and it has already proven useful. I tested it on a weekend trip at a creek and the water came out clean with no strange taste. The first sip takes a bit of effort, but after that it flows easily. The included pouch and hose are a nice bonus for filling a bottle. Feels well-made and I’m confident keeping it in my pack.”
Verified Rating
“Really solid little filter. I keep one in my car and another in my go-bag. Used it after a storm when our well water looked cloudy, and it worked without any issues. The carbon stage improves the taste noticeably compared to other straws I’ve tried. Lightweight, simple to use, and the lifetime warranty gives peace of mind. Highly recommend for anyone who wants a reliable backup water source.”
Verified Rating
“This is one of the better personal water filters I’ve owned. No batteries, no pumping, just dip and drink. The 0.1 micron membrane gives me confidence when the water source isn’t clear. It’s easy to maintain and the build quality feels premium compared to similar products. I’ve already recommended it to several people in my preparedness group.”
Verified Rating
“I was skeptical at first because I’ve tried cheaper filter straws that clogged quickly. This one feels more substantial and the filtration is clearly better. I used it on a multi-day backpacking trip and had no problems with flow or taste. The backwash syringe makes cleaning easy. It’s now a permanent part of my outdoor kit and I’ve already ordered a second one for my wife.”
Verified Rating
“Excellent product for the price. It’s compact enough to throw in a daypack but still filters effectively. I tested it on lake water and the difference was obvious. The accessories (especially the collection pouch) make it more practical than basic straws. Shipping was fast and everything arrived well packaged. I’ll be buying more as gifts for family members who camp.”
Verified Rating
Why choose us
Compare our approach to the alternatives
Our approach
THE WHOLE KIT
Pouch, hose, syringe, carabiner and lanyard. Fill a container for the family.
THE PLAN COMES WITH IT
Three field manuals, free with every order. Real numbers, not filler.
WE SAY WHEN TO BOIL
The filter is one layer. We tell you what to do when it isn't enough.
ONE PER PERSON
Priced so a household can cover everybody.
The alternative
A BARE TUBE
The filter, and nothing else. Lie face-down at the water's edge.
NOTHING TO READ
You work out the rest yourself.
SOLD AS THE ANSWER
No mention of boiling, tablets, or what it can't handle.
PRICED ONE AT A TIME
A family of four buys four times.
The Stronghold Bundle
Everything you need for your next adventure, carefully curated and ready to ship.
What's included:
Premium tactical backpack with lifetime warranty
Water filtration system for safe hydration anywhere
Multi-tool kit with 15 essential functions
Emergency shelter lightweight and compact
Today: $799.00
Everything you need to know
Frequently Asked Questions
What does it remove - and what doesn't it?
Bacteria and protozoa. Those are the two things most likely to be in a
creek, a rain barrel, or water that has been sitting. It does not remove
viruses and it does not remove chemicals. If you think sewage or
chemical runoff is in the water, boil it or use tablets instead. We
would rather tell you that now than have you find out later.
How is this different from a Other?
The filter element is the same technology — 0.1 micron hollow fiber.
What is different is what comes with it. A collection pouch and hose
mean you can fill a container for the whole family instead of lying
face-down at the water's edge. And every order includes the field
manual, which tells you what to do before you ever reach for the straw.
What's in the box?
The filter straw, a collapsible collection pouch, an extension hose, a
backwash syringe for cleaning, a carabiner and a wrist lanyard. The
field manual arrives by email within minutes of your order.
How much water will one filter?
Up to 400 gallons. For one person drinking a gallon a day, that is over
a year of water. Most households will never reach it.
Does it expire?
No. Unused and dry it keeps on a shelf indefinitely. Once you have used
it, keep it from freezing — water left inside can freeze and damage the
fibers. Blow it clear and store it somewhere above freezing.
Can I use it during a boil notice?
Yes. A boil notice usually means bacteria got into the line, which is
exactly what this handles. If the notice mentions chemical
contamination instead, do not filter — use bottled water until it lifts.
What if the water is muddy?
Let it stand for ten minutes so the silt settles, then draw from the
clear part on top. Pouring it through a coffee filter or a clean cloth
first helps too. It will still work on muddy water, it just clogs faster.
Does it work on saltwater?
No. The membrane has to wet through before water moves easily. Give it
a few firm pulls. If the flow slows down weeks later that is silt
building up — push the syringe backward through it and it comes back.
The first sip is hard. Is it broken?
No. The membrane has to wet through before water moves easily. Give it
a few firm pulls. If the flow slows down weeks later that is silt
building up — push the syringe backward through it and it comes back.
Can two people share one?
It has a mouthpiece, so treat it the way you would a water bottle. Fine
within a household, less so between strangers. That is why we sell them
in twos and threes — one per person is the plan.
Can my kids use it?
Yes. It takes a firm pull, so most children over about eight manage
fine. For younger ones, use the pouch and hose so an adult does the
work and the child just drinks.
What if it isn't right for us?
Send it back within 30 days for a full refund. Use it, test it, run a
drill with your family first — that is the whole point of a guarantee.