I use my Steripen Adventurer ONLY for my water bottle for electrolyte drinks. I use it B/C I often need that bike bottle water FAST.

My backup (mainly only for my hydration bladder) is Katadyn Micropur chlorine dioxide tabs. They keep the bladder & hose "sterile".

Filters are SO '90s.
"There are no comfortable backpacks. Some are just less uncomfortable than others."