*Large Volume Water Filter*
NOTE: This is not a water purifier, but a true water filter. It will help clarify water before purification, thereby extending the life of your water purifier. It wiil NOT remove germs or parasites, but will clarify and remove flavors and colors.
This filter should be good for 40 liters of water/day, for up to two months.
TO CONSTRUCT:
Obtain two clean plastic containers, one smaller than the other so that there is at least 1 inch of space between the two when the smaller one is placed inside the larger one. (I used a 1 gallon bucket inside a 2 ½ gallon bucket for my test, but a larger setup would be good for a group camp)
Drill or punch holes in the bottom of the smaller container, at least 1/4 inch in diameter. Water will flow through these holes from the smaller bucket into the larger bucket.
If you have a spigot or faucet, you may install it in the upper side of the outer container. Be sure the installation hole is a little above where the top of the sand and charcoal will be. Install faucet with rubber or plastic washers or plastic gasket cement. Having a spigot on the outer bucket will make it easier to draw off the filtered water.
Place gravel (larger than holes you drilled above) in bottom of large container. Put in enough so that top of smaller container will be even with larger container. Put smaller container inside larger container on top of gravel. Fill smaller container about 1/2 full of clean, fine sand. Cover sand with about two inches of gravel, to hold the sand in place when you pour water into the container.
Fill space between containers with crushed charcoal up to approximate level of top of sand in smaller container. Cover with about two inches of sand to keep charcoal pieces from floating to the surface when water is added.
TO USE:
Clean filter before using water from it. Pour water into the smaller container and draw it off with faucet until water comes out clear. Then run 8 liters of water that has two teaspoons of chlorine bleach through the filter. The filter is now ready for household use. Always pour water into the inner container and allow it to filter into the outer bucket. When water flow drops, replace the top layer of fine sand. If water begins to have an odor or taste after filtering, replace the charcoal.
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