by Mark Alker
August 16, 2013
A clean water source for adventures? the good DrJon investigates
The All Clear from CamelBak is a water purifier that uses ultraviolet light to render more than 99.9% of the bacteria, viruses and protozoa that are present in untreated water, incapable of causing infection. UV light effectively stops the bad guys from reproducing once they are swallowed, making gastrointestinal upsets exceptionally unlikely. The system is extremely simple to use. Collect your water in the 750ml bottle, screw the UV light cap on, hold the button for two seconds and invert the bottle once or twice over the 60-second treatment cycle. You are then good to drink.
The cap is rechargeable via a USB cable, with a full charge taking five hours and delivering 80+ cycles of UV (depending on ambient temperature). This is enough to make 60 litres of water safe to drink. The bulb will last 10,000 cycles before the non-serviceable cap needs replacement.
The speed and ease of use of the All Clear is impressive. The batteries are reliable, even in very cold weather. The UV light cap is durable and CamelBak’s other bottles and caps can be used to fine-tune your system.
It is worth noting that murky water is not adequately sterilised by UV light, as the particulate causes shadowing. UV light needs to be used in clear, very low sediment water or it will not be effective. The water must be drunk relatively soon after treatment because some bugs may be able to repair the cell damage that UV light causes, given enough time, making them infective again. They also need to be used in ‘hard’ bottles (rather than bladders or collapsible bottles such as the Platypus ‘soft bottles’ that can be rolled up once empty), which slightly offsets the light weight and small size.
CamelBak does sell a pre-filter cap for the All Clear. This has a large pore size and will remove bigger debris from the source water prior to treatment, giving the UV a higher chance of being effective. This adds time and complexity to the system and will make it more difficult to fill the bottle, particularly if the pre-filter becomes blocked.
The UV light cap has no mouthpiece, or provision for a straw, so there is the potential to re-contaminate the water when drinking or pouring from the untreated threads of the bottle. Care is also needed so the light is not switched on accidentally while stowed, draining the batteries.
For the gram counters, the 0.75l bottle weighs 103g, the cap 198g and the supplied plain screw top cap and pouch for the UV head is 65g. CamelBak’s drinking straw lids weigh around 55g. With the UV light cap in place, it is 30cm tall and 8.2cm in diameter, so it does not fit in normal bottle cages.
Overall: Given the right circumstances, the All Clear would be an excellent way to purify drinking water. To my mind, this includes foreign travel, where hotel/bunk house water sources are not reliably sterile, or on short, solo overnighters where there is assured, frequent access to low sediment, fresh water supplies. It would be better if the cap had a drinking or pouring spout and there was a bottle cage fitting option.