Learn how to filter water using charcoal, sand, and gravel using a water bottle and cloth filters to keep these layers separated and water flowing through them.
Water is something most people take for granted because it’s so easy to turn on the faucet and fill a glass with the cool, pure liquid. But, there are times when access to clean drinking water is not so straightforward.
In those cases, it’s handy to know how to make a water filtration system.
How to Filter Water Using Charcoal, Sand, and Gravel
If you’re trying to survive in dire circumstances and the only nearby source of water is a stream or lake, a DIY water filtration system could help you stay hydrated without also consuming dirt.
Many people in developing countries learn to build water filtration systems so they can avoid illnesses, although they use a more detailed method than the one covered below. It removes contaminants as well as filtering out debris. The one you’ll learn about below only does the latter.
You may also want to create a water filtration system at home as a project to educate your curious kids and go into depth about how important it is to drink clean water and how even if a water source appears clean, looks can be deceiving.
The kind of water filtration system explained below doesn’t require a substantial investment. It uses easily well-known materials, like sand and gravel, to filter out things like mud. Charcoal is perhaps the most crucial ingredient for removing any stuff you don’t want to drink, and most traditional water filters contain it. Let’s get started.
1. Cut the Bottom off a Small Plastic Water Bottle
Begin by finding a plastic water bottle, like a Gatorade container, and cut about a half-inch off, working from the bottom of the bottle up.
As a point of reference, the neck of the bottle will be the bottom of the filter, and the part with the opening you created is the top. Keep the plastic cap on the top end of the bottle. Some methods of making this kind of filtration system advise making a hole in the bottle’s cap with a screwdriver.
2. Insert a Cloth Filter
The next step is to stuff a soft filter into the bottle and push it toward the neck. A bandana works well as a filter, and it’s a readily found item. Alternatively, you could use several cotton balls or a coffee filter.
3. Rinse the Filtering Materials
Before you start adding substances to the bottle that act as filters, rinse all of them thoroughly. Doing this should mean the first portion of water passing through should have less debris than if you used unwashed materials.
Many traditional water filtering methods you see today rely on special kinds of membranes made from a polymer called PTFE — or, its full name, polytetrafluoroethylene. However, for our purposes of DIYing a water filter system, you’ll want to use more natural materials like sand and gravel or small rocks. Hence, rinsing off these filtering materials is an important step in creating a clean water filter.
3. Prepare the Charcoal
Get another piece of cloth and use it to spread out your charcoal. If you have charcoal from a grill or fire pit, that’s a good source.
Make sure to break the charcoal into small chunks, using an object like a large rock to crush it if needed. After working with the charcoal to make it the desired size, wrap the cloth around the substance tightly. Finally, slide it into the bottle against the first piece of cloth.
4. Add Playground Sand
From here, creating your DIY water filtration system means adding more gravel to assist with the purification. You’ll start with the finest material and add layers of progressively coarser stuff. Put playground sand directly on top of the charcoal layer. You don’t need to wrap it in a cloth before pouring in the bottle, but add enough to fully cover the cloth.
5. Put in Paver Sand
Paver sand — also called polymeric sand — comprises the next layer. When running it through your hands, you’ll notice it’s more likely to have small stones in it that the playground sand didn’t have.
6. Add the Gravel or Small Rocks
The final two layers of this filter are fine gravel and coarser gravel. Depending on your area, you may find it in nature. Due to the modest diameter of the plastic bottle, you shouldn’t need more than a couple of handfuls, equaling an inch or two of coverage.
7. Secure the Contents
You’ve now added everything to the filtration system, and it’s time to make sure all your hard work doesn’t go to waste. Get another piece of cloth and stretch it tightly over the bottom of the bottle. Keep the soft material in place with a rubber band or a cable tie.
8. Pass the Water Through the Filter
You’re finally ready to start seeing the fruits of your labor. Hold your filter over an empty cup and take off the cap. Then, pour water on top of and through the filter and wait for it to come through the neck of the bottle and into the cup. This type of portable water filter is good to take when you go backpacking.
It’s Easy to Filter Your Water at Home
These steps demonstrate it’s not as challenging as some people think to filter water at home or wherever they are. Keep in mind, though, that you still need to use water purification tablets to make the water potable.
Kayla Matthews writes and blogs about healthy living, sustainable consumption, eco-friendly practices and green energy. In the past, her work has also been featured on GRIT, Mother Earth Living, Blue And Green Tomorrow, Dwell and Houzz. To read more from Kayla, follow her productivity and lifestyle blog: Productivity Theory.
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