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DIY Carbon Filter: How To Make Them Without Spending Too Much

water filter

Carbon filtering is the removal of impurities and contaminants with the use of activated carbon. The layer of carbon uses chemical adsorption to get rid of substances that you do not want to have in your water or air. This is done with the help of the Carbon molecule’s large surface area.

When used as a substrate for purification, the carbon’s pore structure will trap the pollutants’ molecules. This is why a carbon filter is ideal for purifying the air, processing gasses and also for the removal of impurities in the water. It can also be used to purify sugarcane as well as recover gold.

Carbon filters are very important when it comes to caring for plants simply because it can help remove chlorine from water. It can also be used to remove unwanted compounds without getting rid of minerals and salts. Unfortunately, buying a carbon filter can be quite expensive. So let’s find out how you can make one:

Things You Need To Prepare

1. Charcoal


This will be your source of carbon. You can also make activated charcoal if possible. Activated charcoal can produce better results since it can help remove impurities better. I highly recommend that you use it if you are planning to make water that is fit for human consumption. Please refrain from using charcoal that is sold in the market for barbecues and grills. These products may contain chemicals that can harm your plants or your body.

2. 2 Liter Plastic Soda Bottles

big bottles

This will serve as the housing unit for the filter. You can also use bigger plastic bottles if you want to filter a large amount of water. You can also opt to use metal cans, just make sure that the tip is tapered.

3. A Sharp Knife


This will be used to cut the plastic soda bottles. You can use an X-ACTO Knife or a craft knife if you do not have a very sharp knife. You will also need to use the proper tools if you are going to use metal in lieu of plastic soda bottles.

4. A Hammer


This will be used to crush the charcoal into fine pieces. If you do not have a hammer, you can use a large, clean rock to crush the charcoal.

5. A Drill

cordless drill

You will need this to make a small hole on the soda bottle cap. You can also use a clean nail or your knife to do this.

If you think preparing all these tools is too annoying, you can always use a multi-tool​ to replace your knife, hammer and even drill.

6. Pieces Of Clean Cloth


This will be used to keep small particles of charcoal out of the water. If you do not have pieces of clean cloth, you can use grass. If the water is not for drinking, you might be able to use old shirts, a sock, sand or a rag.

7. Ash


This will be used to cover the burning wood. You can also use soil or sand if you do not have ash. You might also be able to use water if you need the charcoal ASAP.

How To Make A DIY Carbon Filter

You need to know whether you want the water for drinking or if it will be used only to water the plants. If it will be used for drinking, try to use as much sterile materials as possible. You should also try to make your own activated charcoal. If used for watering the plants, you will still need to use clean materials.

Step 1: Preparing The Materials


You will need to make a campfire out of good firewood. You might need to create a medium sized pile depending on how much water you need to filter. Let the wood burn completely. You can also do this in the fireplace but you need to keep in mind that you will be making a sizeable fire.

As soon as the wood pile has burned entirely, you need to cover it with ash so it will die out. Wait for a day or two before you uncover the campfire and look for the pieces of charcoal. Make sure that they are cool before you remove them. Pick up the ones that are a few inches big.

Crush the charcoal with the hammer on a clean surface. Make sure that it is the size of small pebbles. Cut the bottom of the plastic bottle with your knife and poke a hole on the cap. Put the clean cloth inside the bottle, make sure that you push it tightly inside the neck so that it can filter out the charcoal.

Step 2: Making The Carbon Filter

charcoal in palm

You will be using the carbon from the charcoal to make the filter. Scoop the crushed charcoal and put it inside the plastic bottle. Pack the charcoal as tightly as you can. After adding a few inches of charcoal, you can put a layer of clean cloth again and sand before adding a few inches more of charcoal.

Step 3: Using The Filter

water drop

Make sure that the carbon filter is able to fill at least half of the soda bottle. You can then pour unfiltered water and wait until it slowly drips out of the carbon filter. Catch the water with a container and save it until you get enough. Boil the water if you want to kill microbes and use it accordingly.


water filtering

You do not have to buy an expensive carbon filter if you need one to filter water for your plants. With the use of basic materials and a bit of knowledge, you can easily DIY a carbon filter at home. Once the filter is ready, it can be used to remove contaminants as well as pollutants from the water.

This will allow you to safely use it to water your plants now that it no longer has chlorine. You can also drink the filtered water after boiling it properly but I highly discourage you from doing it unless it is completely necessary. You can also use this to filter stagnant water for survival purposes only.

About the Author Emily Taylor

My name is Emily Taylor, gardening is my passion and I’m looking forward to sharing it with everyone. I know that there are millions of people out there want their backyard and garden be attractive just like their front yard, so I am here to help you create your own backyard paradise.

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