Water Filter Experiment

    When we visited different water companies, we heard a lot about water filtration. Groundwater is naturally filtered through layers of dirt, stone, gravel, and sand. When the water travels through these layers, it is cleaned. This is one of the reasons that many people think that groundwater is very clean.
    Water companies filter the water in this way, too. Water is sent through the same kind of layers before it is sent out to the towns that buy it.
    We decided to test the idea by creating our own water filter. You can try this, too!

Making a water filter

Supplies

A clear plastic bottle

1/2 cup dirt

2 cups sand

2 cups gravel

glass of water

spoon

Step 1: Cut the bottom off of the bottle about two inches from the bottom. This part can be dangerous, so it is a good idea to get help from an adult for this part. Leave the cap on it.

Step 2: Turn the bottle upside down so that you can pour the gravel in it. It works best if you put larger gravel in first because it plugs up the hole that is capped.

Step 3: Pour the sand over the gravel. It will fall through the gaps in the gravel.

Step 4: Mix the dirt in the water.

Step 5: Pour the dirty water on top of the sand in the bottle.

Step 6: Carefully take off the bottle cap and put the bottle spout into a tall glass or some container that can hold your filter upright. Watch the water seep through the sand and gravel. You can see the layers get darker as the water flows down through them.

Step 7: Check out that water! The layers of sand and gravel should take out the dirt in the water.