How To Make A Water Filter

Water is essential to our survival, but what happens if you find yourself in a situation where you have no access to clean water?

You could give in to the unbearable thirst and resort to drinking from a dirty stream, but this could be detrimental to your health.

How To Make A Water Filter

Why put your health on the line when you can improvise? Why not make your own water filter which will ensure the water you drink is free of debris, grit, and dirt?

In this article, we’ll be explaining how you can make your own water filter if you find yourself in a situation where you have no access to clean potable water or a manufactured water filter system.

What you’ll need: 

  • Plastic bottle or a similar type container 
  • Scissors or a knife 
  • Another container to hold your clean water 
  • Clean cotton or cheese cloth 
  • Coffee filter or porous cloth 
  • Charcoal 
  • Sand (fine and coarse) 
  • Gravel or pebbles

How To Make A Water Filter

Now follow our steps to make your own water filter:

Step 1

Using scissors or a knife, cut off the bottom part of the plastic bottle or container you’ll be using as your filter. If your bottle doesn’t have a cap - skip to the next step. 

Step 2

In the plastic cap of the bottle, you’ll want to pierce a hole so that the water can filter out. If you’ve lost the cap, you can instead cut off the top of the bottle for step 1, and then use your knife or scissors to poke several small holes in the bottom of the bottle. These are your drain holes. 

Step 3

Now it’s time to create your 1st layer with the straining fabric. You’ll need to stuff the bottom of the bottle with whatever will act as your strainer, so fine cloth, coffee filter, cheese cloth, or cotton. 

If you don’t have any of these, you can also use sand or grass. You should fill the bottom of the bottle with approximately 3 inches of grass clippings.

This will help to filter out larger particulates and will even give the water a clean taste from the chlorophyll contained in the grass. Then add 3-4 inches of very fine sand.

Don’t forget to be careful when collecting grass clippings. Avoid any poisonous or unidentifiable weeds, and do not use Highway Department sand! That stuff could be packed full of road salt and harmful chemicals. 

Step 4 

Next, you’ll need charcoal. Use charcoal from a campfire, or BBQ charcoal, but avoid using match or instant light varieties as they’re often soaked in chemicals, and you don’t want these in your water.

Use a hammer to break up the charcoal, or, if you don’t have a hammer available, use a rock to break the charcoal down until the particles are as small as possible. 

Now you can create your 2nd layer. Add about 3 inches of the pulverized charcoal to your bottle, and, if you have it available, add another coffee filter or similar material to prevent too much charcoal from being displaced during the filtering process. 

Step 5

Next, you’ll need to add a 3rd layer, which will consist of fine sand.

Pour the finest sand you can find into a 2-3 inch layer in the bottle, but as we said previously, avoid Highway Department sand as you don’t want any nasty chemicals in your water. 

This sand layer, along with the other layers, will help filter out as many particles as possible. 

Step 6

For your 4th Layer, you should use 2-3 inches of coarse sand or, if this isn’t available, try to find some very small pebbles as a substitute. 

Step 7

The 5th layer should be an additional 2-3 inch layer of fine sand.

The reason for this repeated layer is to combine multiple varying filter stages in the same way a reverse osmosis filter system would, as this ensures that most of the particles present in the water are caught.

Step 8

Finally, for your last layer, add a 2-3 inch layer of gravel or small rocks to your bottle to prevent the water being poured in from displacing the sand.

Step 9

Now you’ll want to grab your piece of porous cloth, such as a cotton bandana or cheese cloth, and use it to cover the top of the filter.

Bear in mind that this step is optional but it’s very useful for removing any large debris from the water and also stops the sand being displaced.

Step 10

Now it’s time to test out your homemade water filter! 

To do this, ensure you have a clean container ready and pour some water slowly into the filter while holding it over the second container underneath to catch the water.

You can use something like a plastic cup, or another container to scoop and pour your water. 

Make sure that you pour the water slowly so you don’t disturb the filter layers too much or cause the filter container to overflow. This wouldn’t be ideal, as it’d spill all that unfiltered water into your collection container! 

Step 11

Finally, you’ll need to sterilize your water before it’s suitable for drinking, as despite it being filtered through many different layers, microbes and other tiny particles may still get through.

The easiest way to sterilize your water is by boiling it in a pot or kettle, but if you don’t have any of these to hand, you can sterilize it the natural way - with sunlight.

To do this, pour your filtered water into a clean, clear plastic or glass bottle up to 3/4 of the way and screw on the cap.

Next, shake the bottled water for thirty seconds to release more oxygen into the water. Then place the bottle on a light or reflective surface where it can get plenty of direct sunlight. 

How long it needs to be exposed largely depends on the weather. If it’s a clear day, 6 hours of exposure should be enough, whereas if there’s 50% or more cloud coverage, the water will require 2 days of sunlight in order to be sterilized. 

The Simple Prepper