Gravity, pump, straw and under-sink filters compared by what they remove, how fast they work and what they cannot do.
Key takeaways
- Match the filter type to your household: straw for one, gravity for a family.
- Read the certification and what contaminants it covers.
- Always keep stored water as the first layer.
Know the limits: most portable filters do not remove chemicals, heavy metals or salt, and some do not remove viruses. If flood water or a chemical spill is possible, use stored or bottled water. Follow any boil-water advisory from your public health authority.
Choose by need
Home storageStored water plus a gravity filterCovers the first days, then extends supply from other sources.
Grab and goStraw or squeeze filterLight and cheap. Good backup, not your main supply.
Long outageGravity or countertop systemHigher volume for a family. Check what it removes.
The four types
| Type | Good for | Watch out for |
|---|---|---|
| Straw / bottle filter | Grab bag, car kit, one person | Slow for a family. Check the rated litres |
| Gravity filter (countertop) | A household with no power or pressure | Takes counter space. Needs two containers and cleaning |
| Pump filter | Faster output from a stream or tank | Moving parts. Needs maintenance |
| Under-sink or pitcher | Everyday use while taps work | Needs working water pressure (under-sink) |
What to read on the box
- Certifications: look for independent standards such as NSF/ANSI 53 (health contaminants) or NSF/ANSI P231 or the EPA protocol for microbiological purifiers, and read which contaminants each one covers.
- Filter, purifier or treated: a purifier is tested for viruses as well as bacteria and protozoa. A filter often is not.
- Capacity: total litres per element, and how to clean or replace it.
- Flow rate: litres per hour. A family of four needs 16 litres a day at the 4 L planning figure.
A sensible kit
- Stored water for the first 3 days (see how much to store).
- One filter that suits your household, plus a spare element.
- A way to boil water, used outdoors if it burns fuel.
- A small backup such as a personal filter in each go-bag.
Options to look at
Quick comparison
| Brand | Best for |
|---|---|
| BBerkey | Countertop gravity filter systems |
| LLifeStraw | Portable filters for backup and travel |
| FFrizzlife | Home countertop and under-sink filters |
B
BerkeyCountertop gravity filter systems
Gravity-fed countertop filters for households.
- Gravity-fed, no pump needed
- Check which contaminants each model is rated for
- Plan how you will refill and clean it
L
LifeStrawPortable filters for backup and travel
Personal and gravity filters for grab bags and camping.
- Straw, bottle and larger formats
- Handy as a backup, not your main supply
- Check exactly what each model removes
F
FrizzlifeHome countertop and under-sink filters
Under-sink and pitcher filters for daily use.
- Systems for daily home use
- Compare certifications and filter life
- Check replacement cost
Quick answers
Does boiling remove chemicals?
No. Boiling kills germs, not chemicals. Follow health authority advice.
Do I need a purifier or a filter?
If viruses are a concern in your source, choose a product that states virus removal.