A variety of events can contaminate ordinary, working sources of water. For example, rainstorms, or even worse, hurricanes, can pollute tap-water that is normally clean. In other cases, a pond or puddle may be used as a water source. With a little improvisation these problems can be remedied, allowing for better-tasting, better-smelling water. NOTE: This type of filter will NOT purify water, but is meant to be used in conjunction with a purification method (boiling, iodine, bleach, etc ….)
The figure above illustrates a three-stage water filter built out of a tripod and porous cloth. This simple device is highly effective in cleansing drinking water. I have seen a version of this constructed out of a plastic milk jug that washed up on the beach (a large, plastic soda bottle would work as well.) In this case, the bottom of jug was removed with a knife and a piece of cloth was placed over the jug’s mouth. The inner layers of the filter were the same as in the image: charcoal, sand, and grass.
This idea works well with buckets as well. Punch small holes in the bottom of stackable buckets. Place one filter element in each bucket. Stack them on top of the the clean empty bucket. Gently pour water into the top one. Bottom one only needs boiling to kill microbes to finish the job.
Instead of grass (which might already have impurities and/or eggs laid on the blades of grass) try to use loosely woven cloth or fine gravel/coarse sand. I’ve also seen these set up using 55 gallon drums and a running stream. First barrel water came in the top and then out a few inches above the bottom into the top of the next barrel etc. First filter (grass in the above) was alternating layers of cloth and wood ash. Yes this is how you extract lye. But it also works to kill off most of the beasties in the water and is removed by the charcoal layer. Take the charcoal out and bake it to reactivate it.
Projects such as this water filter can also make for great fun on family outings and camping trips. Again, ensure that the water is PURIFIED before drinking it, and experiment with filters such as this one to improve the look and taste.
Anyone have experience with filters similar to this one?
Other Survival Solutions(This are the most reliable survival books that you can find)