We all have to deal with making our drinking water safe during backcountry trips. Until recently, we could choose to filter, chemically treat, or boil our water to ensure with confidence that it was safe. Each method has its advantages and disadvantages, its adherents and detractors. At the 2005 Outdoor Retailer Winter Market, Meridian Technologies introduced the AquaStar UV Purifier. Meridian has since improved the product, releasing the AquaStar Plus at the 2005 Outdoor Retailer Summer Market. They have continued to make improvements to the product to become the robust ultraviolet light water purifier we review here. If you do not like the hassle of working with chemicals or a standard pump filter (to say nothing of toting the weight of the average pump filter), then perhaps the 3.9-ounce (110-grams), purifier only, AquaStar Plus deserves a closer look.
- Fast. Purifies 1 liter of water in 80 seconds.
- Built-in lantern provides ample light for in-camp use.
- Does not affect the taste of the water.
What’s Not So Good
- Uses non-rechargeable CR123 batteries.
- Does not screw completely tight to Nalgene Canteens which can result in minor leakage when canteens are upended.
- Severely affected by moderately cold air and water temperatures.
|2006 AquaStar Plus UV Water Purifier|
|Measured weight 8.2 oz (232 g); manufacturer’s specification 8.5 oz (240 g) for UV unit with batteries attached to the supplied polycarbonate 1L bottle.|
Measured weight of bottle 4.2 oz (120 g)
Measured weight of UV-C Purifier without batteries 2.6 oz (74 g). Measured weight of batteries 1.1 oz (34 g). Measured weight of pre-filter 0.1 oz (4 g).
|Two x Type CR123 batteries (3 volt photo batteries)|
Approximately 60 purifications cycles per set of batteries.
|Treats one (1) liter of water in 80 seconds|
Lantern function uses three white 5 mm LEDs built into the cap and runs for 15 minutes before auto-shutoff (30 minutes of lamp use is equivalent to one water treatment cycle).
UV-C lamp estimated to last 2,000 hours.
AquaStar Plus operation could not be simpler. Fill your water bottle, screw the AquaStar Plus on tight, push and hold the button for a moment until the UV emitter activates, and that is all there is to it. If the water is turbid or you want to be extra careful, swirl the water around some during the 80 seconds the ultraviolet light is on. To limit the amount of detritus that enters your water when you fill your bottle, simply cover the bottle’s mouth with the provided no-see-um mesh prefilter to block larger particles and debris. Once a water treatment cycle is complete, a green light in the head of the purifier will flash for 10 seconds. Should a purification cycle terminate before the required 80 seconds have elapsed a red light will flash instead, indicating failure to complete.
The cleverly designed prefilter/strainer is a piece of fabric with a drawcord. To use, secure the pre-filter to the top of your water bottle, tighten the drawcord to ensure a snug fit, and then dip your bottle into the water source. The strainer acts like a coffee filter, straining out 200-micron and larger particles from the water. Not as fine as a paper filter, its purpose is nevertheless to remove the larger debris that could block the light from the UV emitter and float unpleasantly in your drinking water. I used the pre-filter in fairly cloudy source water and found it does a nice job of visually clearing the water.
|The fabric pre-filter traps 200-micron and larger particles. Its purpose is to remove debris that could impair the Aquastar’s functionality.|
Built into the AquaStar Plus’ solid plastic head is a lantern made of three white LEDs. The lantern is turned on by quickly clicking the power button twice. Once on, the light remains lit for 15 minutes, then shuts off automatically to preserve the batteries. According to the manufacturer, running the light for 30 minutes drains the batteries the equivalent of one complete treatment cycle. The lantern casts non-directional white light that is more than enough to do all manner of camp chores, or even read a book in your shelter. I found that leaving the bottle full of water improved the lantern’s functionality.
Changing the batteries is a simple task. The thumbscrews on top of the AquaStar Plus can be loosened while wearing gloves but be careful, it is easy to lose a screw. Fortunately the unit works just fine with one locking screw. In warm weather, the batteries power the unit as claimed. However, when the temperature drops the ultraviolet light refuses to run through a complete cycle. With the return of warmer ambient air and/or water temperatures, the unit works normally again.
Meridian Designs claim that the AquaStar Plus can purify 60 liters of water on a fresh set of CR123 batteries. I have found this claim to be about right under warm air and water conditions, but cooler temperatures degrade performance. A more reliable number seems to be about 50 liters per set of batteries. With some careful shopping, you can greatly reduce your cost per liter of operation, as CR123 prices vary wildly.
The AquaStar Plus ships with a polycarbonate 1-liter bottle that has directions and appropriate warnings printed on its side. The combined weight of these two components is 7.9 ounces. The unit can be used with wide-mouth Nalgene Canteens, saving several ounces. The only minor problem with this is that you need to exercise some care screwing the purifier on to the Nalgene Canteen, since the fit is not quite as secure as the standard cap. If you keep your water bottle upright, the worst you will likely see is a very slow accumulation of water around the threads. If I ever lost water during the course of a typical backpacking day, it was minimal.
The AquaStar Plus in its polycarbonate bottle. A water treatment cycle is in progress.
Despite several weeks of use and several flights stowed in airline luggage, the AquaStar Plus has shown no signs of wear and tear. While I have no doubt that the AquaStar Plus is more vulnerable to failure than treatment chemicals, I have not taken any special care with it. The unit has ridden in an external pocket of my Gossamer Gear Mariposa on several trips and has fallen from out of that pocket onto the ground a few times (as the result of my own falls). I have no doubt that placing the AquaStar Plus inside the hard-sided confines of a polycarbonate bottle will improve overall durability, but the purifier has functioned well inside my Nalgene Canteens.
The market for UV water treatment systems is still fairly new. The AquaStar Plus represents a well-thought out and implemented entry into this new arena of water treatment. In our fast-paced world of plug-and-play items, the AquaStar Plus provides almost instant gratification when it comes to treating water.
Recommendations for Improvement
Overall the AquaStar Plus is a well-designed product. It has some limitations but most are unavoidable, like the power requirements. This is not a knock against the AquaStar Plus, since all water treatment tools have limitations. One design change that would be nice to see is the use of captive screws for the battery cover.