After two hikes, this is my ‘go-to’ water purification system for ‘flowing water’ sources (contrasted to ‘still water’ sources, e.g., ponds and lakes). Katadyn BeFree (Rei page)
This is so light and easy to make small, I carried it in pant’s back pocket after drinking what I needed. Filtering a larger amount for the next day was also fast and easy. A side benefit is that I am not committed to filtering all that I take … if too much, dump it without wasting filter.
I now carry 2, and recently in Enchanted Valley, gave 1 to my hiking partner whose different tool failed. … I quickly bought another so there’s a primary and backup.