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#5 on this list
Ultra
SteriPEN
UV purification for clear water — kills viruses and protozoa without touching flavor.
- Price
- $390 MSRP
- Reader rating
- No reader votes yet
- How we assessed it
- Specification researched
#6 on this list
GravityWorks 6L
Platypus
Best group filter — hang a bag, fill bottles for four people. Standard base-camp system.
- Price
- $390 MSRP
- Reader rating
- No reader votes yet
- How we assessed it
- Specification researched
Specs side by side
| Spec | Ultra | GravityWorks 6L |
|---|---|---|
| Purification Method | UV Light | — |
| Effective Against | Viruses, Bacteria, Protozoa | — |
| Treatment Time | 45-90 seconds per liter | — |
| Power Source | Integrated USB Rechargeable Battery | — |
| Weight | Approx. 140g (5 oz) | — |
| Filter Type | — | Hollow Fiber |
| Capacity | — | 6 liters dirty / 6 liters clean |
| Flow Rate | — | 1.75 liters per minute |
| Removes | — | Bacteria, Protozoa, Particulates |
| Total Weight | — | 12.2 oz (345 g) |
| Filter Lifespan | — | 1500 liters |
What our reviewers liked and didn't
Ultra
- Neutralizes viruses, bacteria, and protozoa effectively
- No impact on water taste or chemistry
- Lightweight and highly packable design
- USB rechargeable battery, convenient in the field
- Fast treatment time for individual servings
- Does not filter out sediment or particulates
- Requires clear water to be fully effective
- Battery dependent, needs recharging
- UV lamp is fragile if dropped or impacted
GravityWorks 6L
- High volume output ideal for groups
- Hands-free operation once set up
- Reliable and proven filtration technology
- Relatively lightweight for its capacity
- Easy to backflush and maintain
- Not ideal for solo or ultralight trips
- Requires suitable hanging point
- Slower than pump filters for immediate water needs
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