5 TO CHOOSE FROM...

Lifesystems Chlorine Dioxide Water Purification Tablets £9.99

Unlike typical chlorine treatments, these tablets leave no noticeable aftertaste. They’re light and packable, and while they won’t get rid of particulates in the water, they will kill bacteria, viruses and cysts in water including Giardia and Cryptosporidium.

LifeStraw Personal Water Filter £27

This device is used like a straw to filter water as the individual sucks it up, whether drinking water direct from source (such as a pool or river) or water collected into a bottle. It removes 99.9999%, and 99.9% of protozoa, reduces muddiness and weighs just 57g.

MSR TrailShot £60

Whether being used to drink direct from the source, or to fill up a bottle or bladder, the hand-pumped TrailShot filters out almost all (99.9%) bacteria, protozoa, and particulates. It can treat 1 litre of water in 60 seconds and is compact enough to fit in the stash pocket of a rucksack.

Katadyn BeFree Gravity Water Filtration System 3L £70

Holding 3 litres of water, the BeFree Gravity system is perfect for base camps or larger groups, where it can be hung up and left to do its thing, using gravity to filter up to 2 litres of water per minute, removing bacteria, cysts and sediment.

Steripen Adventurer Opti UV Water Purifier £95

The Steripen utilises UV light to eliminate bacteria, protozoa and viruses. It doesn’t remove sediment, and the water needs to be reasonably clear for it to work, but it’s a neat and rapid (90 seconds per litre) alternative to filtering, for which it can also be used as an additional treatment.