Simple filter set-up , if you're not using ditch water. www.camp-cook.com :: View topic - DIY Gravity Water Filter
Can A water filter be this easy???
It can be even easier. This is what I got and I sent a mini off with a missionary going out of country.
Pay attention how many gallons these small filters can handle.
Amazon.com : Sawyer Products SP181 PointOne All-in-One Filtration Kit with 32-Ounce Squeezable Pouch : Camping Water Filters : Sports & Outdoors