In some extreme scenarios you may need to clean your water, so know how to make your own water filter is a good idea. Also, it is a great activity to do with your kids!
We tried different methods and selected our favorite approach to create the best water filter possible in a short number of steps.
Check below the steps and materials required to do your own water filter, and if you want to drink the filtered water after, don’t forget to boil it first.
To make your own water filter, you need the following materials:
- Empty and clean water bottle, with a cap
- Water cup or mug (to collect the filtered water)
- Scissors or craft knife
- Coffee filter, clean cotton, or cheesecloth
- Activated charcoal
- Clean sand: fine and coarse
Step #1: Cut off the bottom of the bottle
Cut off the bottom of the water bottle with the scissors (ask the help of an adult for this task, if you are a child).
This will be the water filter container where you will add all the different filtering layers.
Step #2: Open the drain hole
Cut a hole in the water bottle cap with scissors. The filtered water will pass through this hole to the water cup.
Use scissors or a knife to poke a small hole in the cap.
Step #3: Create the 1st layer – coffee filter
Now it’s time to create the 1st layer of your filter. We will count from bottom to top, so this will be the bottom layer.
Use a coffee filter (alternative use cotton or cheesecloth) to fill the bottom of the bottle, with one to two inches.
This initial layer will prevent the material of the next layer, activated charcoal, from falling out to the water cup and act as the final filter.
Step #4: Create the 2nd layer – activated charcoal
Now for the 2nd layer, we will use activated charcoal – break it into small pieces and create a layer with two to three inches.
To break it you can put pieces into a small bag, close it, and use something heavy to hammer the bag and reduce the charcoal into smaller pieces.
Some people ask if they can use regular charcoal instead of activated charcoal on this layer, and the answer is no. Activated charcoal has oxygen added, and removes some chemicals and bacteria from the water that passes through it.
Step #5: Create the 3rd layer – fine sand
For the 3rd layer, add two to three inches of fine sand to the bottle.
You can use a strainer to separate the finer sand from coarse sand, and you will have the materials for both layers.
This fine sand layer will filter small contaminants and particles that passed through the top layers.
Step #6: Create the 4th layer – coarse sand
To create the 4th layer, just add two to three inches of coarse sand on top of the previous fine sand layer.
As in the previous layer, this will help to filter out small particles and contaminants that were not caught on the top layer.
Step #7: Create the 5th layer – gravel
For the top and final layer, the 5th one, add two to three inches of gravel or small rocks on top of the sand layer.
Make sure you leave at least one inch from the top of the bottle until this last layer, to have some room to pour water without spillover if it is not filtered quickly enough.
This final layer will not only filter out the larger particles but will also prevent the water that is being poured from displacing the materials used on the other layers, like sand.
Test your homemade water filter
Now that you made your own water filter, you need to test it!
Just put an empty water cup on the table, hold the water filter above it, and pour some water slowly into the filter, and keep pouring more water making sure it doesn’t spill out of the filter.
After you filter all the water you can repeat the process, now using the filtered water – you may want to run the filter process a couple more times until the water is clear.
Boil the Water
If you want to drink the water that you just filtered, you need to boil it first for around 3 minutes. Some pathogens, bacteria, and viruses can only be killed with high temperatures!
DIY your own water filter is a great activity, and if you live in an area where the quality of water isn’t great, you should really consider buying a good water filter.
Having your own water filter is not only a healthier choice, but it’s also eco-friendly because you will reduce the number of plastic bottles you use, and can be a life-saver in an emergency scenario.
Check read our water filter guides to help you choose the best filter for you and your family!