Building a good quality water purification filter that can last for years is easier and cheaper than you think. Don't spend hundreds of dollars on a pre-built purification system, and instead follow this guide to create your own.
Steps
Method 1 of 2: Filter By Gravity
Step 1. Gather what you need
You will need two 20-liter non-toxic plastic buckets (i.e. polypropylene) with a lid, and a food-grade plastic tap. You will also need a couple of water filtration elements. These items will be the biggest expense you will have to incur in the entire project.
- Make sure your filter elements are BRC or NSF certified.
- Get a drill with ½-inch and ¾-inch bits.
Step 2. Drill the necessary holes
Later you will put the buckets on top of each other to allow gravity to pass the water through the filters. Drill two ½-inch holes in the bottom of the bucket that will stand on top. These holes should be made symmetrically with respect to the center and along the diameter of the bucket.
Drill two corresponding holes in the lid of the bucket that will stand underneath. The holes should line up when the buckets are placed on top of each other
Step 3. Drill a ¾ inch hole for the faucet in the bucket that will stand underneath
Assemble the tap, making sure it has a good seal, so that no water leaks from the edges of the hole or from the tap itself when it is closed.
Step 4. Install the filter elements
These must be mounted in the bucket that will stand on top. The nozzle of the filtering component must be fixed through the holes made in the bottom of the bucket which is placed on top. Make sure both filters are firmly attached. The nozzles should then protrude a few centimeters from the bottom of the bucket.
Step 5. Stack the two buckets
The outlets of the newly assembled filter component should enter directly into the holes drilled in the lid of the lower bucket.
Consider whether it would be convenient for you to seal the gap between the two buckets. This is useful if you don't intend to move your sewage system very often and helps prevent dust and dirt from getting into the gap between the two buckets and contaminating the clean water supply in the lower bucket
Step 6. Start purifying
Fill the upper bucket with water. It may take some time for the water to start seeping through new filter components. This process will become faster as the filter elements are used.
Continue adding water to the top bucket to increase the speed of the filtration process. Higher water pressure on the filters helps make them run faster
Step 7. Clean your filters
As the solid residues of the not yet filtered water accumulate at the edges of the filters, the speed of the filtration process will decrease. Clean your filters with a plastic brush (such as laundry brushes) to keep them working properly. If the water you want to purify is cloudy, carry out a preliminary filtration by passing it through a clean folded cloth or rag to remove the larger solid residues.
Method 2 of 2: Purify Without Using Filters
Step 1. Boil the water
Bringing to a boil is notoriously the safest way to purify water. If the water is cloudy, pre-filter it using a folded tea towel or coffee filter.
- Boil the water for a full minute, then let it cool and then drink it or use it to prepare food. If you are more than 600 meters above sea level, boil it for three minutes.
- Add a small amount of salt to the water while it is boiling to improve its flavor.
- Make a charcoal filter using cotton. A filter consisting of fragments of activated carbon stuffed into a cotton ball is able to eliminate impurities and partially improve the bad taste of the water that has been boiled when it is filtered through it. Activated carbon will also remove some toxins from the water that other filtration methods would not be able to eliminate.
Step 2. Add some bleach to the water
The use of bleach should be limited to situations where it is not possible to boil water. Make sure the bleach you want to use does not contain flavorings or soap. Household bleach should contain approximately 5-6% chlorine-based bleaches.
For two liters of water you will need to add 5 drops of bleach. Stir vigorously and then leave to rest for at least 30 minutes. If the water is particularly cloudy, double the amount of bleach and let it sit for at least 60 minutes
Step 3. Use the SODIS to purify the water
SODIS, from the English solar disinfection, is a water disinfection method that uses sunlight. Half-fill clear PET bottles with water. Shake them repeatedly to help oxygenate the water, then fill the bottles to the brim and plug them. Place the bottles in a place that will be lit directly by the sun for at least 6 hours.
- This method works best when the bottles are tilted so that they are perpendicular to the sun's rays and are resting on a conductive material, such as a metal roof or piece of corrugated sheet.
- Glass bottles are not good for taking advantage of this effect, as they block the UV rays essential to produce it.
