Water Treatment

Filters are the most popular method of ensuring water collected in the outdoors is completely safe to drink, and there are a lot of choices from pump filters to gravity filters from respected brands such as MSR and Katadyn, as well as newer brands such as HydroBlu. The lightest option could be chemical treatment though, for example Micropur tablets weigh virtually nothing, the only compromise compared with a filter is they don't remove particulate matter, but if you expect clear water sources such as running rivers then they could be the best option.