======Homemade Water Purifier Model======


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**Materials: **{{$demo.materials_description}}\\
**Difficulty: **{{$demo.difficulty_description}}\\
**Safety: **{{$demo.safety_description}}\\
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**Categories:** {{$demo.categories}}
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**Alternative titles:** Make a Water Filter
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====Summary====                   
{{$demo.summary}}



====Procedure====  
  - Ask an adult to cut a clean 2-liter plastic bottle in half. Place the top half upside down into the bottom half to form a funnel.  
  - Place a coffee filter, bandanna, or paper towel at the bottom of the funnel section.  
  - Add filter materials (cotton, charcoal, gravel, sand, etc.) in distinct layers. Record the order of your layers.  
  - Stir dirty water (mixed with soil, coffee grounds, leaves, or oil) and measure out one cup.  
  - Pour the dirty water slowly into the filter while timing how long it takes to pass through. Record the result.  
  - Observe how clear the filtered water looks. Scoop out each layer of filter material and note what impurities it trapped.  
  - Rinse and repeat with different filter material orders to test how layering affects filtration.



====Links==== 
Make a simple water filter experiment - SydneyWaterTV: 
{{youtube>H1ae2dIVsIw?}}\\

DIY water filter experiment - Aberdeen Science Centre: 
{{youtube>pU3gAK3Xyhs?}}\\

📄 Make a water filter - National Geographic Kids: [[https://kids.nationalgeographic.com/books/article/water-wonders]]\\

📄 The Dirty Water Project:
Design-Build-Test Your Own Water Filters - ncwit.org: [[https://www.teachengineering.org/activities/view/cub_environ_lesson06_activity2]]\\


====Variations====
  * Test different filter materials such as paper towels, cotton cloth, or sponges.  
  * Compare coarse versus fine sand layers.  
  * Try different amounts of charcoal to see if it improves clarity.  
  * Time how long water takes to pass through short versus tall filter stacks.



====Safety Precautions====
  * An adult should cut the bottle with a utility knife.  
  * Do not drink the filtered water—it may still contain harmful microorganisms and chemicals.  
  * Wash hands after handling dirty water.  
  * Dispose of filter materials properly.




====Questions to Consider====
  * Why does water move more slowly through filters with finer materials? (Because smaller spaces between particles trap smaller impurities.)  
  * What role does activated charcoal play in the filter? (It attracts and traps tiny particles and chemicals using electrical charges.)  
  * Which order of materials made the cleanest water? Why?  
  * Why is the filtered water still unsafe to drink, even if it looks clear? (It may still contain bacteria, viruses, or dissolved chemicals.)  
  * How do natural water systems, like wetlands, act as filters in the environment? (They slow water flow and trap sediments, plants absorb pollutants, and microbes break down waste.)