With a little ingenuity and a few parts (of about $30 or less) you can build your own SHTF DIY water filter which can be reused over and over again.
You only need an inexpensive hand pump, activated carbon, window screen material (or something similar), a small piece of PVC pipe, as well as some appropriate fittings and tubing to round out the build.
Of course, this water filter should ONLY ever be used as a last resort and you really should attempt to boil any collected water to ensure it’s safe to consume. This filter, therefore, should be considered as a quality pre-filter before final treatment…[Amazon Affiliate Disclosure: As an Amazon Associate I earn from qualifying purchases. FTC Disclaimer: I get commissions for purchases made through links in this post.]