Which Sagan Life systems does this filter fit?

It is made for the XStream Straw, AquaDrum, AquaPod and RapidFlo Gravity Filter. It is not a universal cartridge and will not fit other brands' purifiers.

How often should I replace it?

Replacement depends on how much water you treat and how cloudy or silty it is. Sagan Life sets a rated volume for the filter; once you near it, or flow slows noticeably, swap in a new one.

Does it come with the housing or straw?

No. This is the filter cartridge only. The straw, drum, pod or gravity housing is sold separately and is reused.

Will it remove bacteria and protozoa?

The Journey is the purification stage of Sagan Life's systems, which are marketed for freshwater sources. Follow the system's own rating for what it removes, and treat very turbid water with care.

Can I store a used filter between trips?

Let it drain and dry as the system instructions say before storing. A damp filter left sealed for months is more likely to clog or grow odor.

Is it worth it versus a new purifier?

If your Sagan Life housing is intact, a replacement cartridge is the sensible choice. Buy a new system only if the housing or straw itself is damaged.