Water is considered as the most vital element in our life. all living things( humans, animals, and plants) needs water to progress in their life. In this instructable, I will show you how to filter water in an easy way that is replicable in classrooms and educational classes and also for survival situations. This method can be applied in chemistry classes focusing on water where students will interact easily and they learn some survival tips to filter water if they were camping. This project consists of four layers that work as obstacles to filter water but it doesn't sterilize it, I will show in an example of water and soil mixture and how it filters the water from the soil so it separates them from each other, and become valid for washing as an example. These procedures only clear the water and make it more palatable, you will have to purify it.

Step 1: Materials Needed

All that you need in this instructable is from nature, so don't worry about the materials.

Sand (sea sand is better)
cotton
small and medium-sized stones.
relatively big-sized stones
water
empty bottle
cutter

Step 2: The Four Layers

In this project, I referred basically on four layers for the filtration system. So you have to place several centimeters or layers of filtering materials. The layers are set from the small ones to the biggest size one, the first layer from the bottom of the bottle is cotton, the second layer is sand, then small and medium-sized stones and the last layer is big stones.

This process will filter and remove the odor from water, also you can add charcoal as an additional layer. Charcoal is also helpful in absorbing some agricultural and industrial chemicals.

Step 3: Cut the Bottle

First, you should cut an empty bottle from the bottom to place the layers. In my case, I used a small bottle so I have small layers but you can use bigger size bottles so there will be big sized layers and be able to filter more water.

Step 4: Add the First Layer

The first layer consists of cotton, where cotton is made out of fibers connected to each other, so this layer can filter water more than the others and more.

Step 5: Add the Second Layer

The second layer is sand, and I prefer to add sea sand to the bottle since it is better the normal sand. What sand does is when passing flocculated water through a rapid gravity sand filter strains out the floc and the particles trapped within it, reducing numbers of bacteria and removing most of the solids.

Step 6: Add Small Stones

The third layer consists of small to medium-sized stones; while adding them to sand be careful to set them tightly to don not make big gaps between them, so that water can hardly pass through.

Step 7: Add Big Stones

The last layer is big-stones and this layer is optional where you can just make one layer of the same size make the small ones. So if you prefer to eliminate this layer you can replace it with charcoal that will be better also.

Step 8: Prepare It for Testing

After adding all the layers together, prepare a container to collect the filtered water. I used a glass cup to hold it and collect water or you can use a container and hold the bottle with a clamp.

Step 9: Test It!

Let's test it!

First I prepare a mixture of water and soil, then I added it to the filtration system and it works well.

Step 10: Clear Water

Succesful experiment.

Step 11: NOTICE

This is a failed one that I like to view it for you. What happened with me is that after using it more than one time it doesn't function properly. I realized that the first layer made out of cotton will not function properly after many uses, so the solution is to simply replace it with new cotton from the other side of the bottle.