CAMELBAK Lifestraw Replacment filter 
This simple plug and paly LifeStraw Filter turns the humble water bladder into a filtered water chamber.
Take the question mark out of the water collected on the trail with a simple 2 stage filter that is both easy to install and use.
 
This filter whole made for the Cambel Pack quick release port they work with other bands that share theis quick release ports. Check to see if yours in compatable. 
All components are free of BPA, BPS, and BPF.
Two Stages of Filtration:
Stage 1: Hollow Fiber Membrane Removes 99.999999% of bacteria (E. Coli, etc.), removes 99.999% of protozoa (Giardia Cryptosporidium, etc.), removes 99.999% of microplastics, filters 4,000 litres (1,000 gallons)
Stage 2: Activated Carbon Filter, reduces chlorine, removes bad odor and taste, filters 100 litres (25 gallons)