How to make your own water filter?

Water is essential to survival. It is important for water to be pure and fresh. Do you know that 80% of diseases are waterborne? So it is important that our drinking water should be safe and fresh. It is a reality that the water supplied at our home is not always fresh and germ-free; therefore water filters are crucial.

Did you know that you can make your very own filter?

But how is it possible? For this, first we have to know the basic theory of water filtration. In homemade water filter we pass dirty water through the layers of sand, gravels, charcoal, and when dirty water passes through these layers the dirt or impurities are filtered away. As a result we get clean water. But keep in mind that if you want germ free or bacteria free water, you will have to boil the water or add chlorine to it.

A list of things that are required to make your own water filter are shown in the picture below. These are:

  • a plastic bottle,
  • a large mug,
  • filter paper,
  • gravel,
  • sand,
  • activated charcoal and
  • hammer and knife.
Image Source

Please remember to use knives, hammers or drilling machines only in your parents’ presence.

Let’s start step by step.


  • Cut the bottom of the plastic bottle using a knife.
  • Make a hole in the cap of the bottle so that water can pass through it. For this you can use anything like hammer and nail, scissor, or any drilling machine.
  • Now cover the mouth of the bottle with filter paper and affix the cap tightly over it.

  • Take the mug and set the bottle in the mug keeping the cap side down.
  • Now, first pour charcoal inside the bottle through the upper open end and fill up nearly one third of the bottle. Ideal size of the charcoal granules is like rajma or pea (common food item).
  • Then, fill the bottle with sand. Thickness of sand layer should be same as the thickness of charcoal. Another thing is that you can use two types of sand, fine grained sand and coarse grained sand. In this case fine grained sand will go first and then coarse grained sand.
  • In the end, make the top layer with gravel. But do not fill it completely, keep about 2 inches free.
  • Now your water filter looks like the picture below. Set your water filter in the mug as shown here.

Pour water in your water filter through the opening on the top and water will pass through layers and clean water will come out through the hole in the bottle cap and collect in the mug below.
Now the question is how does it work?

You can see that in the above water filter we have used different layers off gravels, sand, activated charcoal and each layer has a particular purpose. Each layer of your water filter acts as a strainer. On the top we have gravel or stones. This layer filters out some bigger particles like leaves, insects etc. Next layer is sand layer and this filters out fine particles like dust, dirt etc. Finally we have used activated charcoal. Activated charcoal is made by burning wood or similar type of things and it is used to remove chemical impurities, pesticides etc.

But, remember, this water is not germ free or bacteria free. So, you will have to boil or add chlorine to this water to make it totally safe for drinking. Also, you need to regularly clean it or replace the material used to use it for long time. Do you know, why we need to clean water filters regularly?

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