Activity: Water Filtration

Sam with her filter.

On SCOPE's Water episode, you saw Samantha filter some creek water using things from around her home. Here's how she did it. Watch the clip. TRANSCRIPT OF CLIP..

Warning: This activity involves creeks and water and careful supervision is needed when walking about the edges.

What you need

• Funnel
• Coffee Filter Paper
• Coarse Sand
• Cotton Wool
• Tea Strainer
• Creek Water

What to do

1. First you'll need a sample of creek water.
2. Start by putting the coffee filter into the funnel and filling it with sand
3. Next add a layer of cotton wool above the sand.
4. Then hold the tea strainer over top your filter and pour the water.
5. Make sure you have a clean container underneath to catch your filtered water!

What's happening?

Muddy creek water doesn't look like good old clean H₂O, but with a few household items you can create a water filter to clean it (a scoop at a time).

The first stage of your filter, the tea strainer is just like the screens they have a water treatment plants, its job is to collect the large debris so it doesn't clog up the system.

The cotton wool is next and it will trap some of the larger particles that managed to elude to tea strainer.

Finally, the water passes through the sand. Sand is actually a really good natural filter and sand beds are used in some parts of the world to filter city water supplies. Sand can filter out some kinds of common bacteria as well as help settle out very small particles due to the slow speed the water moves through it. The coffee filter is mainly there to hold it all in place, although it will also catch a few fine particles.

It might look nice and refreshing but microscopic bacteria can still live in it so its best not to drink it but your plants can.