Water pollution is a serious issue that affects millions of people around the world 
. It can be caused by:
Agricultural activities 
Industrial waste 
Household garbage and sewage 
To help tackle this problem, you can build a simple and inexpensive water filter using basic materials. Here’s how:
What You’ll Need:
A plastic or glass container with a hole at the bottom 
Coarse sand 
Small stones or gravel 
Activated charcoal (from a pharmacy or crushed charcoal) 
A plastic or glass tube for drainage 
A lid or cork to seal the filter 
Steps to Build the Filter:
Add a 5 cm layer of coarse sand at the bottom of the container.
Pour a layer of gravel or small stones on top of the sand.
Add a layer of activated charcoal above the gravel.
Insert the drainage tube through the hole at the bottom.
Seal the container tightly with a cork or lid to prevent leaks.
Pour dirty water into the top and watch as cleaner water flows out from the tube.
This basic filtration system helps improve water quality for household uses. (Note: The filtered water is not safe to drink unless it is boiled or treated further.)