Membrane Solutions Straw Water Filter S1 - Compact Survival Filter

Our review of the Membrane Solutions Straw Water Filter S1 finds it best suited for hikers, campers and anyone assembling an emergency kit who needs a simple, portable way to get drinking water. The single biggest reason to buy is its combination of a true 0.1 micron hollow fiber stage and an easy, pocket-sized straw form factor that fits standard 28mm threaded bottles, delivering reliable filtration without heavy gear. It performs as a lightweight, long-life backup for outdoor use and travel when treated water sources are not available.

Key Features

• 5-Stage Filtration: A coarse screen, double-layer PP cotton, coconut shell activated carbon and hollow fiber membrane remove particulates, improve taste and reduce many contaminants for safer drinking water.
• 0.1 Micron Pore Size: The smaller pore size increases filtration accuracy while still maintaining a usable flow rate of about 500ml per minute, so you get cleaner water without long waits.
• Portable Size: At 7.1 in long and 1 in diameter and only 2 ounces, the straw fits in a pocket, backpack or survival kit and works with standard 28mm threaded bottles.
• Long Service Life: The design and replaceable ends extend usable life and the filter is rated to provide up to 5,000 liters (about 1,320 gallons) of drinking water under typical conditions.
• Food-Grade Materials: Constructed from BPA-free ABS and food-grade plastics for safe contact with drinking water and durable everyday outdoor use.

Who It's For

The S1 is ideal for solo hikers, weekend campers, scout groups and households building an emergency preparedness kit who want a lightweight, reliable way to turn uncertain water into drinkable water. It works well as a personal filter for travel where bottled water may not be available or trusted.

Those who need to treat very large groups frequently, require chemical disinfection, or must reduce dissolved solids (TDS) should consider larger pump or gravity filters and complementary treatments, since this straw does not lower TDS and is optimized for personal or small-group use.

Pros & Cons

Pros

• Very compact and lightweight, easy to carry in a pack or pocket for outdoor trips.
• High filtration accuracy with a 0.1 micron hollow fiber membrane for clearer water and improved taste.
• Multiple filtration stages including activated carbon for odor and taste improvement.
• Long rated life up to 5,000 liters when used and maintained as directed.

Cons

• Some users report occasional short-term failures, so performance can vary and routine testing or backups are prudent.
• Does not reduce TDS or replace the need for chemical disinfection if viral contamination is a concern.

Specifications

Our Verdict

The Membrane Solutions Straw Water Filter S1 is a practical, value-oriented choice for outdoor enthusiasts and emergency preppers who need a compact, effective personal filter. Its 0.1 micron hollow fiber membrane and multi-stage filtration offer trustworthy performance for drinking water in the field, while the small size and long rated life make it a smart backup or daily carry option for many users.

Frequently Asked Questions

Will this filter remove viruses?
Answer. The straw uses a 0.1 micron hollow fiber membrane which removes bacteria and protozoa and improves clarity, but viral removal is not guaranteed; additional disinfection methods are recommended for viral risk.

Can it fit my water bottle?
Answer. Yes, the straw is designed to fit standard 28mm threaded bottles, cups or glasses and also works with soft water pouches.

How long does the filter last?
Answer. The manufacturer rates the filter up to about 5,000 liters (1,320 gallons) with proper use and maintenance, though real-world lifespan depends on source water quality.