Dirty water should be clarified before purifying it. An inexpensive filter for clarifying water can be made from an empty 2-liter plastic bottle and a paper filter such as those used in coffee machines. Cut off the top of the 2-liter bottle just below the shoulders. Turn the cut-off top upside down into the bottom of the bottle. Put a paper filter into the cut-off top. Poor dirty water through the filter. Purify the clear water that runs into the bottle by boiling, bleach, a commercial water purifier, or other methods found at “Water Storage and Purification.”
Another method of water clarification is by capillary action. Two large containers, such as buckets, and a heavy towel are necessary. Place one container on the floor. This will be the catch container. Put dirty water in the second container and raise it several inches off the floor or place it on a chair next to the empty container. Place one end of the towel in the dirty water with the end of the towel touching the bottom of the container. Put the dry end of the towel in the empty container on the floor with the end above the expected final water level. Over several hours, the water will move up the towel and down into the catch container. The dirt will stay in the towel and the water in the catch container will be clear and ready to purify by boiling, bleach, a commercial water purifier or other methods found at “Water Storage and Purification.”
NOTE: Water filtration devices work by physically filtering out protozoan cysts and bacteria. Water purification devices filter protozoan cysts and bacteria and also remove viruses which are too small to be removed by a filter.