Backpacking water filters

Three things decide which filter suits you. The first is pore size: 0.1 micron is the common rating that stops bacteria and protozoa. The second is rated capacity, which varies enormously between models, from a few thousand litres to hundreds of thousands. The third is how you want to use it. A squeeze filter or straw is the lightest option and works straight off a bottle, a pump draws from shallow sources, and a hose filter can be built into a larger setup. Travelling outside Europe or drawing from water you cannot judge? Carry purification tablets as well. Spare cartridges, backflush syringes and hoses sit under water filter accessories.