Water wash

Before you begin

• Make some dirty water by mixing soil, mud, and water in a large clear bottle. It’s even better if the soil contains bits of dried leaf, grass, and other debris. Shake it well to mix.
• Use scissors to cut the clean, empty plastic bottles. Cut the top third off—it doesn’t need to be an exact measurement as long as the bottom section of the bottle is noticeably bigger than the top part. You might find it easier to pierce the bottle with the point of the scissors first.
• Set up tables with the same equipment on each: one cut empty bottle, cotton wool, paper napkins, and gravel or stones. Set up one table for each group—it’s up to you how many groups you want to have.

Talk about water

1. Everyone should think about the difficulties some people go through to access clean and safe drinking water.
2. The person leading the game should explain that millions of people live without easy access to water.

Follow the above link 'Water, toilets and hygiene' to find out more information.

Make a water filter

1. Everyone should split into groups and each group should go to a table with equipment.

You may want to give everyone a letter from ‘water’ or ‘H2O’ to create groups.

2. Each group should put the top half of the plastic bottle (with the bottle top) upside down inside the bottom half. The top half should rest inside the bottom half, like a funnel. The funnel-like top half will be the filter, and the bottom half will hold the filtered water.
3. The person leading the activity should show everyone the bottle of dirty water they’ll be filtering.
4. Each group should decide what order to layer the materials in their funnel to make their filter. They can use as much or as little of each material as they like.

You may want to remind groups that the dirty water has things of different sizes and textures inside it. They’ll need to filter the bigger things (such as sticks and leaves) first, and then the smaller particles like dirt).

Test the water filters

1. Once each group has finished their filter, the person leading the activity should test each one by slowly pouring some of the dirty water in the top.

Don’t forget to protect the floor (or table) with plastic sheets or newspaper, and clean up any spills right away so it doesn’t get slippery.

2. Everyone should talk about which filters worked best, and why. They should rearrange the materials (or add or take away materials) to see what works best.
3. The person leading the activity could rinse or wipe out the bottles, so everyone can have another go.
4. At the end, the person leading the activity should get rid of all of the water by emptying it down a drain or sink. No one should drink the filtered water as it may still be unsafe.