Water covers two-thirds of the Earth's surface and makes up about 60% of an adult's body, including 75% of our brains!
It is recommended that we drink more than two liters of potable/purified water per day. And thanks to the professionals working in public health to ensure we have a supply of safe drinking water free of impurities we can all drink to meet these needs.
Despite the abundance of water on our planet, our potable/clean water supply is not easy to drink. (eg frozen in a glacier or sea water). Even fresh water can contain waterborne diseases or contaminated water.

1. Pour lake water into a 2-liter bottle with a lid. Pay attention to how it looks and smells.

2. Put the cap on the bottle and shake vigorously for 30 seconds. Then pour the water back and forth between the two cups about 10 times.

3. Pour water into the bottle and cut off the top. Again, notice how the water looks and smells.
4. Add 2 tablespoons of alum to the water in the bottle and cut off the top. Stir the water slowly with a spoon for five minutes. What do you notice when you stir the water?

5. Now let the water sit for 20 minutes, check it every five minutes and notice how it looks and smells (don't move it).
6. Use a rubber band to secure the filter paper to the mouth of the bottle and cut off the bottom. Invert it in a beaker.

7. Pour ordinary activated carbon into the bottle. Then pour the crushed medical stone on the activated carbon, and pour the fine coconut shell carbon on the crushed medical stone.

8. Carefully pour in about two liters of clean tap water, being careful not to disturb the activated charcoal on the top layer. Pour the rinsed water out of the beaker.

9. Pour the top 2/3 of the lake water into the filter, taking care to leave the sediment in the lake water bottle.

10. Once all the water has passed through the filter, compare the swamp water with contaminants to the filtered water. How do they look and smell different?