Ultraviolet irradiation has been used for some time in industrial and home water purification systems, but is new to the portable arena. Meridian Design introduces a portable UV-C purifier that screws onto a standard quart Nalgene bottle. AquaStar kills anything with DNA including protozoa (giardia and cryptosporidium), viruses, and bacteria. The unit weighs 3.1 ounces with two CR-123 (camera type) batteries and 8.5 ounces fully assembled with a polycarbonate (Lexan-Nalgene-type) bottle. The bottle protects the AquaStar from damage and keeps UV-C from eyes. Press a button on the side of the unit for a few seconds and 1 minute later, 1 liter of pure water. Two doses are needed for water below 50 ºF. At 35 ºF and lower, the unit has been designed not to operate since the UV tube becomes very inefficient at generating UV-C. The User Manual recommends warming cold water to 40 ºF and then dosing it. One set of batteries will purify about 70 liters of water. Filtering through a coffee filter is recommended for water with sediment, since sediment can shade organisms from UV-C light. The light tube lasts 2,000 hours.
Weight: 8.5 ounces is not bad for a unit that purifies 1 liter of water in 1 minute, but it’s more than most lightweight backpackers want to carry for water treatment. The Nalgene bottle is heavy and takes up extra pack space since you’ll probably purify the water and put into another container for drinking and cooking. I talked to the inventor, Kurt Kuhlmann, and asked how the AquaStar could be configured lighter. Ditching the Nalgene saves 5 ounces, but the light tube needs to be protected. The tube can withstand some abuse, but not being thrown into a pack unprotected. The light tube unit can be screwed onto a soft-side Nalgene Cantene (Kurt suggests sloshing the water in the Cantene a couple of times during the 1 minute of irradiation to make sure all areas of the water are “hit”) or suspended in a container of water (the surface of the water will safely reflect UV-C rays from the eyes), but some means of protecting the light tube is needed when it is not in use. I suggested a cigar tube. It sounds like Kurt is mulling this all over and might develop a slim threaded tube to cover and protect the light tube if enough lightweighters are interested in this product.
The light tube is 7/8” in diameter and fits into an Aqua Fina bottle mouth but not a narrow mouth bottle. However, water must cover a gold pin at the top of the tube which is mounted on the bottom of a white plastic cylinder 1 ¾” in diameter. The cylinder will not fit into the Aqua Fina mouth so the Aqua Fina bottle would need to be filled to the brim for water to even touch the pin – which might not be effective. The tube can be held suspended in a water container with an opening larger than 1 ¾”. The AquaStar will treat larger volumes of water than 1 liter simply increasing dosage as appropriate.
- Weight UV-C unit: 3.1 oz
- Total weight as shipped, with bottle and batteries: 8.5 oz
- Displacement volume in full bottle: 2.6 oz (78 ml)
- Batteries: 2 CR-123 batteries
- Water treated per battery set: 70 L
- UV-C tube: Philips Germicidal Sterilamp with rated useful life as used in AquaStar of 2,000 hours
- Dosage time: 60 seconds per 1 L (1 cycle). Below 50 ºF dosage time should be doubled.
- MSRP: $95 including batteries and bottle
- Website: www.uvaquastar.com
Of note, the other portable UV purifier that I know of is the Steripen, which weighs 8 ounces with four alkaline AA batteries and 6.4 ounces with lithium batteries. MSRP is $150. One set of alkaline batteries will treat 10 – 20 liters of water, and one set of lithium batteries 65 – 70 liters. Purification of 1 liter of water takes 90 seconds.
Backpacking Light has a unit to test; results will be published when available.