Brief Hiking Bio

I learned camping and hiking in Boy Scouts, tramping the Washington Cascade foothills, and eventually took up backpacking as a singular pursuit and found a home away from home in the Cascades and Olympics. Now living in northern California, most of my hiks are in the Sierra Nevada, the trips ranging from overnight to weeklong excursions. Total pack weight for three-day summer trips, including food and water, is now roughly 25 pounds (12 kg), longer trips see pack weights ranging into the mid to upper 30s (15-17 kg).

Product Information

Name and model:	AquaStar Plus!
Maker:	Meridian Design, Inc.
Website:	http://uvaquastar.com
Year of manufacture:	2005
Product type:	Battery-Powered Ultraviolet Water Sterilizer
Options:	None available
Ships with:	Instructions, batteries (2x CR123A)
Specified weight:	8.5 oz  (240 g) w/batteries and bottle
Measured weight:	7.4 oz (210 g)
Treatment cycle time (measured):	84 seconds
Projected battery life:	60 treatment cycles
Minimum water temperature:	35 deg F (2 C)
Projected UV lamp life:	2,000 hours
Warranty period:	Two years
MSRP (US$):	$95
Country of Origin:	U.S.
Report date:	January 24, 2006

Tester Information

Tester:	Rick Dreher
Email:	redbike64(at)hotmail(dot)com
Male
Height:	6 ft (1.83 meters)
Weight:	175 lb (79 kg, 12.5 stones)
Age:	51
Location:	Northern California, USA
Years backpacking experience:	39
Backpacking skill level:	Mid to advanced
Backpacking Style:	Lightweight alpine and subalpine travel

[Note: The test AquaStar Plus! is an early production model. Several running changes have been made in the meantime; they are notated below.]

Introduction

AquaStar Plus! is a self-contained water sterilization system that uses ultraviolet light in the “C” spectrum (UV-C) to inactivate biological contamination: viruses, bacteria and protozoa, including cysts. The battery-powered UV generator is essentially a fluorescent tube that inserts into the supplied, screw-top 1-liter (34 fl oz) bottle. It operates immersed in water for about 80 seconds per cycle, during which it renders microorganisms harmless so that the water is fit to drink. The Plus! model tested is the second generation AquaStar which features several design tweaks along with an added LED light that converts the water bottle into a lantern for nighttime use.

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Long-Term Test Summary

As fall became winter I continued using AquaStar Plus! on my day hikes. For this task it performs well, once I warm the near-freezing source water inside my jacket. As the maker advises, the unit won’t cycle as the water approaches freezing and even when it will cycle, they recommend a double-cycle. I settled on a bicycle bottle (24 oz [700 ml]) as my standard on-trail container, preferring its slender profile and the greater ease of prewarming a lesser amount of water. I never learned to enjoy tucking a cold, wet bottle inside my jacket but it actually works pretty well. I’m on my fourth battery set, and believe that the 60-cycle projected life is a little optimistic, but the extra stress of cold-weather use certainly plays a part, as does lantern use. In any case, at 33 g (1.2 oz) toting an extra set is really no inconvenience.

Product Design and Materials

AquaStar Plus! comes in two pieces: a clear, 1 L (34 fl oz) polycarbonate bottle and the works: a UV emitter tube jutting from a threaded bottle cap that houses the batteries and circuitry. The thread diameter and pitch are similar, but not identical to those used in the familiar Nalgene brand wide-mouth bottles.

The bottle is helpfully printed with instructions and graduated volume measurements, including minimum and maximum fill lines for treatment. Polycarbonate isn’t the lightest bottle material but it’s very tough and in my experience, imparts no plastic taste to water.

The works are waterproofed and protected from physical shock, although the quartz glass tube is exposed and therefore, susceptible to damage from the side (necessary, as covering it would block UV light output). Atop the cap’s threaded portion is an extension with a battery cover on top and the power button on the side. The single button controls all AquaStar functions. Two screw closures on the battery cover can be opened either using a slotted screwdriver or by hand, using the foldaway bails. One of the screws sports a rubber hang loop. The circuitry enclosure extends into the bottle below the threaded top and the tube emerges from that extension.

Two CR123A 3-volt lithium cells power the AquaStar Plus! These relatively common camera batteries reside beneath a battery cover that has molded polarity symbols (+/-). The cover is shaped to only go on in one direction. Note: the battery cover screws aren’t held captive and can be lost.

The user manual has four pages of instructions and helpful FAQs covering nearly every aspect of operation and troubleshooting, as well as the theory behind UV sterilization. Additional information is available at the AquaStar Website.

Running Product Changes

As part of this long-term report I contacted the maker for a summary of product updates. Chief Technical Officer Kurt Kuhlmann kindly detailed the improvements made since production began last summer:

• The head has been fixed so that it fits very nicely on all Nalgene tops now.
• The clear part (translucent cap extension and battery cover) has been fixed to be even more watertight, and won’t crack in the very cold.
• The confirmation light runs longer at 10 seconds and always runs the white lantern mode too, as that is more visible in bright sunlight.
• It’s now supplied with a nylon mesh prefilter (shown on the Webpage).

Purifying

AquaStar Plus! is easy to use:

1. Fill the bottle with any amount from 300 ml to 1 L (10 to 34 oz). Note: don’t fill to the top because the tube displaces some water when inserted, and some airspace is required for agitation.
2. Insert the works and twist closed.
3. Press and hold the power button for about 2 seconds.
4. Slowly invert and return the bottle throughout the treatment cycle—about 84 seconds.
5. When the lights indicate treatment’s done, the water can be consumed.

The treatment cycle can be halted at any time with a button push, useful if simply testing the unit or treating a small portion of water.

Prefiltering is called for with cloudy or debris-laden source water. Depending on the type of material in the water, this might be accomplished using a physical filter, settling it out or chemical flocculation.

Low batteries and/or cold water prevent a compete treatment cycle. The unit shuts down, accompanied by a flashing red LED beneath the power button. A green LED indicates normal operation. The manufacturer’s projected battery life is about 60 normal treatment cycles, theoretically treating 60 liters (16 gal) of water, and recommends doubling the treatment time water that’s cloudy or below 50 F (10 C).

The Lantern

Double-clicking the power switch activates the lantern feature. A white LED shines downward from the cap into the bottle, creating a soft and fairly even glow. The light is dispersed further when the bottle is filled with water. To conserve battery life, the light shuts off after about 15 minutes (dimming a minute before). Each lantern cycle is estimated to use 1/100^th of the battery life, or slightly less than consumed by one treatment cycle. Of course, the light can be switched off at any time.

Long-Term Test Results

I’ve used the AquaStar Plus! extensively and with good success for summer and fall backpacking, and day hikes through midwinter. As noted in the field report, the original batteries failed in the cold but fresh replacements quickly brought the unit back to life. I was later able to squeeze several more warm weather treatment cycles out of those originals and I’m now on my fourth battery set, meaning I’ve used the AquaStar for close to 200 cycles.

When camping, I’ve adopted a 48 oz (1.5 L) Nalgene Cantene as a treatment vessel. The thread match isn’t perfect--it’s tough to screw on and can leak--but the increased container volume speeds water collection and treatment for the evening’s camp. On the trail I use a slender 24 oz (700 ml) bicycle bottle because it fits better inside my jacket or in a backpack side pockets than the standard 1 L (34 oz) bottle. The AquaStar threading fits the cycling bottle perfectly, and both optional containers are lighter than the supplied Lexan bottle, but lack the handy instructions and aren’t as rugged.

The green and red LED cycle indicators beneath the power switch are difficult to see in direct sunlight but fortunately the flashing white end-of-cycle LED is quite visible. In dimmer light I can see the colored indicators.

For debris removal I use a clean bandana, folded to double or quadruple thickness. It’s not always easy to prefilter this way directly from the source; I’ve found pouring the water into the treatment bottle from another container, such as a cookpot, speeds the job. Fortunately I’ve not needed to prefilter muddy, silty or algae-filled water, which would require more aggressive filtration than porous fabric.

AquaStar has survived numerous freezing nights without harm. I’ve learned to not tighten the lid in the evening so it doesn’t freeze shut. If I have relatively warm source water I don’t have to thaw out the works before using AquaStar in the morning; otherwise, a few minutes inside my coat melts any ice and warms the electronics.

Long-Term Test Goals, Answered

I launched this test with several questions:

• Ease of use? AquaStar Plus! is simple and relatively fast. Collecting a couple gallons of water for an overnight camp for two (six treatment cycles) takes about fifteen minutes; collecting a liter on the go takes about two, or as much as ten if I have to preheat the water.
• Reliability? Only battery failure, easily remedied by adding a new set.
• Effectiveness? I’ve not acquired any waterborne illnesses to my knowledge.
• Completeness? AquaStar now recommends rinsing threads with treated water to flush away any contamination.
• Battery life and cost? I never did a cycle count to failure and because I used different size containers and the lantern function during this test, I wasn’t able to generate a reliable count in the field. However, based on my informal counts I believe 50 cycles is readily achievable with name-brand batteries--more cycles than that in warm conditions. CR123 store prices I see here in California range from $3 to $10 each, while on-line generic brands can be as little as $1 ea. Presuming 50 cycles per battery set, the treatment cost per liter can range from 40 cents to 4 cents, so it pays to shop around!
• Low battery warning? In my experience there’s not a reliable warning of impending dead batteries, the unit will simply fail to complete the treatment cycle and flash the red failure signal.
• Lantern function? The lantern is a nice feature. While it isn’t useful for camp chores, it’s a nice shelter light and I can read by it. I especially like the auto-shutoff. 
• Low temperatures? Low ambient and low water temperatures do affect AquaStar performance. To combat cold temperature problems I’ve relied on fresh batteries and body heat. On the trail it takes five to ten minutes under my coat to adequately warm a liter of freezing cold stream water sufficiently to cycle the AquaStar.
• Wear, tear and ruggedness? No problems, despite some inadvertent drops and several nights below freezing. The bottle is a little scratched but the imprinted measuring lines and instructions live on. I’ve managed to hang on to the two cap screws.

Long-Term Test Conclusions

AquaStar Plus! has proven easy to use and competes well against chemicals and filters. I can operate the controls in the dark when it’s cold and wet. Compared to chemical treatment, the AquaStar imparts no taste to the water and requires no premixing or long treatment cycles. Compared to pumping, the AquaStar’s fill-the-bottle-and-push-the-button ease and simplicity are hard to match (gravity filters, while slow, might be considered even less work). That said, even at 48 oz (1.5 L) per treatment cycle it takes several rounds to accumulate an evening’s worth of water for camp.

In my opinion, AquaStar Plus! isn’t a prime winter camping treatment option; there are less-painful ways of gathering the volume of water required for overnight use. But on the wintertime trail, if there’s running water available it’s reasonable to use AquaStar to meet my hiking needs (and it’s much, much easier than stopping to melt snow). If for some reason I were to use take the AquaStar winter camping, I’d mix stove-heated water with source water to raise the temperature, then treat. I definitely don’t have the spare body heat or spare time to warm it a liter at a time under my jacket. Again, this would be much quicker than melting snow.

The lantern function is nice around camp and in the tent and, because it automatically switches off it’s especially nice not to worry about falling asleep while it’s running.

I am as impressed by Meridian Design as I am of the AquaStar. The rapid and continued refinement of the product bespeaks a commitment to making AquaStar as useful and reliable as possible. Their responsiveness to my queries is as good as I’ve ever experienced.

After these several months of use, AquaStar Plus! gets Rick’s highest recommendation, front row in my gear vault for future three-season camping trips and year-round day hikes.

Suggestions for Improvement

Use captive screws on the battery cap and tether the cap itself to the works. Add a stick-on thermometer to the bottle.

My thanks to Meridian Design, Inc. and BackpackGearTest for the privilege of participating in this test.

--RTD