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:	80 seconds
Projected battery life:	70 treatment cycles
Minimum water temperature:	35 deg F (2 C)
Projected UV lamp life:	2,000 hours
Warranty period:	Two years
MSRP:	$95
Country of Origin:	U.S.
Report date:	September 23, 2005

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:	38
Backpacking skill level:	Mid to advanced
Style of backpacking:	Lightweight alpine and subalpine travel (see bio at end of report)

Introduction

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

Most backcountry water treatment is in the form of filtering or chemical sterilization. Filters can directly remove debris, bacteria and protozoan cysts from source water without adding chemicals. Some filters will also remove chemical contamination and a select few remove viruses. Chemical treatment will inactivate viruses and bacteria and, in many cases, cysts as well. The strengths and weakness of filters and chemical treatments are well known and each has its adherents and detractors.

AquaStar is one of but two (that I’m aware of) products for travelers using a very different approach to providing safe drinking water in remote areas: it applies lethal radiation in the form of ultraviolet light. As such it neither adds nor removes anything from the source water; it simply kills whatever living organisms are in the raw water. [Note: I do not know what effect AquaStar Plus! might have on certain “exotic” biological contaminants such as parasite eggs.] Thus, AquaStar does not affect the water’s taste or remove debris.

Product Design and Materials

AquaStar Plus! comes in two pieces: a clear, 1-liter (38 fl oz) polycarbonate bottle and the works, which are basically a UV emitter tube jutting from a threaded bottle cap that contains 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 (more on that later).

AquaStar Plus! carries this warning sticker on the potential hazards of UV-C:

“WARNING Do NOT look at bare lamp. Keep away from children.”

Virtually any container the AquaStar Plus! might be used in will shield users from 100% percent of UV emissions, so there’s no reason to don eye shields or slather on the SPF 50. Just don’t switch it on when it’s out of the bottle.

The bottle is helpfully printed with instructions and graduated volume measurements, including a maximum fill line for treatment (the tube displaces some water when inserted and airspace helps agitation). Polycarbonate isn’t the lightest material to make a water bottle from but it’s very tough and unlikely to impart a plastic taste to water.

The works appear thoroughly waterproofed and are protected from physical shock, although the quartz glass tube is exposed and susceptible to damage from the side (necessary, as covering it would block UV light output). Atop the cap is an extension with a battery cover on top and the power button on the side, this is the AquaStar’s only control. The cover has two screw closures that can be opened using a slotted screwdriver or by hand, using the foldaway bails. One screw sports a rubber hang loop that looks like an o-ring. The circuitry enclosure extends into the bottle below the threaded top and the tube emerges from that extension. A reinforced wire conductor runs alongside the tube from the works to the tube’s protective end-cap. The tube extends about 7 inches (18 cm) into the bottle, ending less than an inch from the bottom. The bare tube section is about 3 ½ inches (9 cm) long, this is the actual emitter portion. The entire works, from top to tip, are 8 inches (20cm) long and the bottle and cap combined are 9 inches (23 cm) tall and 3 ½ inches (9 cm) wide.

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

[Note: The test AquaStar Plus! is an early production model but should not differ from production models available in stores. However, the draft user instructions available at the time of this initial report likely differ from those to be supplied at retail. Any significant changes from what’s presented here will be noted in future reports.]

Operation

AquaStar Plus! is easy to use:

1. Fill the bottle to the indicator line (or with as little as 300 ml).
2. Insert the works and twist closed.
3. Press the power button for about 2 seconds.
4. Slowly invert and return the bottle throughout the treatment cycle—about 80 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 less than the maximum bottle capacity.

With cloudy or debris-laden source water, some kind of prefiltering is called for. I’ve not explored the options but a simple few layers of cloth over the bottle opening collect most large debris. Removing fines might take more aggressive measures.

Double-clicking the power switch accesses the lamp feature. A white LED shines downward from the works into the bottle, creating a soft and fairly even glow. The light is dispersed more evenly when the bottle is filled with water. To conserve battery life, the light shuts off after about 15 minutes (dimming at 14 minutes as a warning). Each lantern cycle is estimated to use 1/100^th of the battery life, or slightly less than required by one treatment cycle. Of course, the light can be switched off at any time.

Low batteries and/or cold water will prevent the AquaStar from completing the treatment cycle. These conditions are indicated by the unit shutting down and a red LED signal from beneath the power switch. A green LED at the switch indicates normal operation. Projected battery life is about 70 normal treatment cycles, theoretically good for 70 liters (8.5 gal) of water. Also of note is that the makers recommend doubling the treatment for cold (below 50 F/10 C) water.

The AquaStar is powered by two CR123A 3-volt lithium cells, commonly used in cameras. They’re installed beneath the top cap, which is held closed by the two screws. Polarity indicators (+/-) are molded into the battery cap, which is shaped to only go on in one direction. Note that the screws aren’t held captive in the battery cap and can be lost

Initial Test Results

I was able to use the AquaStar within a couple minutes of taking it out of the box—it’s that simple. Once the UV emitter tube fires up it emits a pleasant blue glow. I used the same long-forgotten darkroom technique I used to agitate film while processing to keep the water moving inside the bottle. The goal is to ensure that all water has sufficient contact time with the UV radiation to kill any bad guys. That’s why it’s important to have some airspace in the container: agitation is much more effective when there’s air present.

There’s no need to wait between treatments, simply empty the water to a larger container and repeat as often as necessary. I timed the treatment cycle at an average of 84 seconds, meaning that a gallon (4 L) of drinking water can be obtained in a little over five minutes. This compares favorably with most filters and chemical treatments I’ve used.

According to my scale, the 7.4 oz (210 g) total weight divides between 3.8 oz (108 g) for the bottle and 3.2 oz (91 g) for the works, somewhat less than specified by the maker.

The green and red indicator lights beneath the power switch are difficult to see in bright daylight, but the white LED that flashes to indicate end of cycle is obvious in all conditions I’ve yet experienced.

I’m able to perform a battery swap in about a minute. In dim light I replace the batteries one at a time to ensure polarity without having to check the cap markings. The supplied batteries are generic “Titanium PowPower” brand. I’ve found CR123s can range widely in cost, from roughly $1.50 each for generic brands bought in bulk on line to as much as $6.00 at the corner store. Obviously, battery cost will affects the cost/volume operation and I’ll attempt to track battery usage during the test.

Alternate Containers

Gram-weenies and gearheads will automatically look at the supplied polycarbonate bottle and think about alternatives, which is what I’ve done. The AquaStar folks give some general container guidelines that include sticking with rigid containers, ensuring that containers are long enough to accommodate the tube, and increasing the number of cycles for containers larger than a liter.

While it would appear at first glance that any standard Nalgene wide-mouth container should accommodate the AquaStar Plus! emitter, this only proved to be partially true. My stock of Nalgene bottles and Cantenes (soft-sided containers) are the right diameter but the threads bind with the AquaStar, some more than others. However, several of my bicycle bottles fit perfectly. A trip to the local backpacking emporium with the unit in hand bore the same results: some containers fit well and others not so well. I came home with a 48-ounce (1.4 L) Nalgene Cantene that fits fairly well, although it’s a bit tricky to fit it to a tight seal. Note that the works need to travel in a rigid container to protect the tube, a soft-sided container can be used for treatment but not for storage or transport.

My container goals are fourfold. First, not all my backpacks accommodate the 1-liter bottle in their side pockets so a smaller bottle, such as a cycling bottle, makes a handy substitute. Second, a larger container will speed treatment of larger water volumes, presuming the shape supports effective circulation and treatment time is adjusted accordingly. Third, a white or translucent container increases the lantern mode’s effectiveness. Finally, the 3.8-ounce (108 g) stock bottle isn’t the lightest alternative out there.

Initial Conclusions

The AquaStar Plus! is easy to use and fun too, for a gadget geek (guilty!). The controls couldn’t be simpler, and slowly inverting the container during treatment is much less of a hassle than working a pump or mixing chemicals. The new lantern function is a nice surprise and may prove a pleasant tent companion. The batteries change-out process is gratifyingly simple and easy to perform. If it works half as well in the field as it does at home, this might become my favorite water treatment option of all!

Suggestions for Improvement

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

Field Test Goals

I’m very curious about battery life in the field and the effects of cold, especially as winter now approaches. Will there come a time when it’s simply too cold to use this device in the field? Also, while the AquaStar Plus! is designed to protect the UV emitter tube there’s still ample opportunity for a clumsy person like me to shatter it and render the unit useless (the tube isn’t user-replaceable). Along with spare batteries I’ll likely carry some sort of chemical backup.

I hope to answer the following questions during this test:

• Ease of use—how easy is AquaStar Plus! to use in the field? How agitating will the required agitation be if I want a couple gallons of water for camp (eight treatment cycles)?
• Effectiveness—My days in micro lab are far behind me; however, sometimes I can see small organisms in source water, particularly lake water. Will they fry like an ant under a magnifying glass? Inquiring minds want to know!
• Completeness—do I need to be concerned about untreated water trapped in the threads?
• Battery life and cost—how long (number of cycles) does a set of CR123s last and can I find inexpensive ones locally?
• Lantern Function—is it worth decreasing battery life to use the AquaStar Plus! as a lantern? What tasks can I perform using in the light it gives?
• Field maintenance—how easy is it to swap out the batteries in bad conditions? How useful and accurate is the low battery warning?
• Temperature monitoring and low temperature performance—I can’t predict what my water temps will be, but it’s easy to envision encountering cold water during the four-month test. How much of a factor will water temperature be? Will there be times when I can’t raise the temperature enough to treat? Should I carry an immersion-type thermometer? Can I find a stick-on thermometer with the appropriate range for the bottle?
• Prefiltering options—if I must use turbid water, what are some simple filtering options?
• Alternative containers—what else might I use?
• Wear, tear and ruggedness—drops happen, so how rugged is the AquaStar Plus!?

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 hiking is 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 (17 kg).

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

--RTD 9.23.2005