If you've ever bought a filter for a home water purifier, you realize the refill accounts for a good amount of the price of the entire piece. Want a bigger one for a campsite or a mobile home and you can easily pay three figures.
Simple Garden Water Filter
Many of the parts for this water filter can be found in pet store that stocks aquariums. Gravel, activated charcoal and a milk juice or plastic juice bottle are just about everything you need. If you're tight on funds (or far from a pet store), you can also pick up rocks from a stream and use charcoal from fire. Beware: You'll want to avoid chopping up chemically treated charcoal briquets because they can add chemicals rather than remove them.
As MIGardener explains, this setup removes about 80 percent of the impurities, which is fine for most garden watering, but for drinking water, consider one of the more advanced purifiers described in the videos below.
Survivalist Water Filter
The water filter made by Ultimate Survival Tips adds to the charcoal system by adding sand (coarse and fine) as well as cloth (cotton or polyester). While the water will likely be cleaner with this method, you may need to run it through the system a couple of times. Boiling it is also smart for removing more contaminants.
For this water filter, a small Gatorade bottle makes the design a little more portable.
DIY Campsite Water Filter
For a campsite water filter that handles several gallons of water, Far North Bushcraft and Survival combines a DIY approach with manufactured pieces. Inspired by a $240 water purifier, the design attaches five Doulton Ceramic Water Filters to a repurposed five gallon plastic food container (one that's often used to hold olives packed in liquid and other wet ingredients). After the water drips through the ceramic filters it's then stored in a second plastic food container of the same size, stacked underneath the first.
This setup costs about $160 less than the mass produced one that inspired it.
Straw-Style Water Filter
Desert Sun also employs charcoal as the main ingredient of this compact filter. Packing the carbon into the bottom section of a turkey baster, along with a little wadded up cotton and a coffee filter, makes it possible to sip water through it like a straw.
This may not be the best backpacking water filter, but it can certainly help in a pinch.
Two Stage Water Filter (Carbon and Heat)
For campers who want to take their water filtration and purification to a new level, this two-stage system lets the water drain through charcoal and then feeds it through a heated coil that boils the water and lets it drip into a jar. An open-flame system like this may only be suitable for a campsite, but the two stages remove about 99 percent of the impurities in any water.
If only it was easy to make this system a little more portable.