I have 4 walter filtration devices picke dup over the years.
1. Steripen bought years ago and used for 1st time last week on a trip in the Us
2. Aquaguard Eliminator Inline filter, use when I use a hydation systm
3. Aquamira bottle filter, picked up for 20$ in Waltermart as it was cheape than buying a filter for my aquaquard.
4. Aquamira straw filter, got with the above one for 10$
All have advantages and disavantages.
When using the steripen and bottle filter I use a 3ltr platy for the dirty water and filter when I want it.
cheers,