How To Make A Water Filter At Home (DIY Tips For Everyone)


As the whole world is affected by the Covid pandemic, many people are forced to stay home more forto avoid getting infected. As a result, this is also the opportunity to learn a new thing and expand your knowledge.

If you’re interested in some new survival skills, don’t miss out on our DIY tips on how to make a water filter. The below sections will provide you with a detailed process of making a water filter with only simple home tools. Rest assured that a DIY filter can somehow purify your water until it’s safe enough to drink (backed by science). Let’s start and see if you can pull it off. 

Things You Need Before Making A Water Filter

Needless to say, a self-made water filter can become your savior under severe situations, such as when you happen to be short of clean water.

This type of DIY water filter relies on the principle of removing contaminants from large particles to smaller ones. For that reason, each layer of fabric, sand, and charcoal has its own indispensable role for the efficient operation of this filter design. Finally, activated carbon exerts a key impact by purifying the water because it can absorb the impurity. 

But, before you can grasp how to make an effective water filter, make sure that these tools are around and ready to use:

  • A plastic bottle (any size)
  • A knife or scissors to cut plastic bottles
  • A container for filtered water
  • Cotton wool, a clean cloth, or coffee filter paper
  • Cobblestone or small greenstone
  • Fine sand
  • Activated carbon
  • The soil in a potted plant or the garden
  • Water

How To Make A Water Filter (Step by Step Instructions)

  1. Use a knife or scissors to cut off the bottom part of the plastic bottle. Make sure the bottle remains most of its length.


  1. Fix the cut plastic bottle on top of the water tank with the bottle mouth turned down and the bottle cap removed.
  2. Place the bottom filter layer, consisting of cotton wool, a clean cloth, or coffee filter paper, into the plastic bottle so that the it is at least 2 inches thick.
  3. Crush the activated carbon and put it on top of the cotton wool layer. The ideal activated carbon layer thickness is approximately 1 inch.
  4. Spread over 2 inches of activated carbon with pebbles or small rocks.
  5. Next, add 3 inches of fine sand (or sea sand) into the bottle.
  6. The final layer of this homemade water filter will be another 1 inch of cobblestone.


Make sure that after finishing putting in the last filter layer, the plastic bottle still has about 1-2 inches empty for you to pour water in.

How To Test The Result & Effectiveness Of Your Water Filter

First, get 2 glasses of clean water from your tap. Turn 1 of these 2 glasses of water into “dirty water” with soil in a potted plant or in the garden. 

Also, you can put in the “dirty water” cup with cooking oil, tea or coffee grounds, or other spices in the house, depending on your creativity, to turn it into a natural dirty cup of water.

Then, gently pour the dirty cup into your water filter. Remember to do it slowly; otherwise, the top layer of rock may overflow, or you will unexpectedly mess up all the below layers. Attentionally monitor the flow of running water inside the filter and see how its color changes after getting down each layer.

After that, you can clearly tell the difference between the initial cup of clean water and the one that has run through the filter.

Finally, don’t forget to boil the filtered water so that you can remove the remaining pathogenic bacteria that may still exist. After this stage, feel free to drink it. 


Frequently Asked Questions

What If During The Filtration Process, The Cotton Wool Or Cloth In The Bottle Drifts Down And Slips Out?

If you don’t want the weight of the sand and rocks on top to cause the cotton fabric to slip out of the bottle, create a few small holes in the plastic bottle cap and then close the bottle as usual. The bottle cap will hold all the ingredients inside, and the small holes in the bottle cap will allow the filtered water to escape.

To What Size Should The Activated Carbon Be Crushed?

Activated carbon is actually charcoal, so it is very brittle and easy to break. You just need to gently beat it until the charcoal gets as small as half of the bean.


Can The Water After Being Put Into The Filter And Boiled On Can Be Drunk?

It depends on what ingredients you put in in the beginning. If at first, the way you make a cup of “dirty water” is to add only edible ingredients such as cooking oil, coffee grounds, tea grounds, cooking spices, rice, etc., then you can drink it in order to better distinguish the effect of the water purifier. Hopefully, your water purifier is working correctly, and it doesn’t taste too bad.

If you initially put in soil from your potted plant, garden soil, dishwashing liquid, or other inedibles, the best advice is not to try it. The reason is that this homemade biofilter is only a test subject; it is still not as reliable as a sophisticated and modern filter out there for you to drink it with peace of mind.

Why Should You Learn How To Make A Water Filter?

There are many reasons for you to do this experiment.

First, it is useful. Water is something that we cannot survive without for more than three days. Meanwhile, water purification plants can only filter 3% of the water on Earth. 

Hence, knowing how to make drinkable water from non-potable water such as groundwater and oceans will help you understand the importance of clean water.

Besides, it’s an interesting way to learn new things without costing you a fortune. The things you need to prepare before making a DIY water filter are simple to find. Last but not least, this is also an important skill to survive dangerous situations. 

How Many Ways Are There To Filter The Water?

There are many water purifiers with different operating principles. These include biological water purifiers with sand and activated carbon, solar energy, alum and chlorine, fabric water purifiers and water purifiers, water purification by ion, etc. Among them, a homemade water filter by the process that the article just mentioned is the simplest and most suitable for doing at home.


This step-by-step guide may sound a little bit complicated at first, but once you get the hang of it, you’ll find it pretty easy and practically helpful. 

That’s our guide on how to make a water filter at home. Not only is it a rewarding experiment, but it can also create quality time for your own good. I hope you found the article helpful. Also, don’t forget to share it with your loved ones if you like it. Good luck.