This instructable would be a great water filter to design with students especially those in upper elementary or middle school. The simple design of the filter will allow the user to filter out large and small particles as well as clear the water sample to some degree. I made this to show students how the different physical properties of materials can work together to form a function for everyday life. The water filter is made from everyday household items and can be constructed in a short period of time. The instructable also includes directions on how to create a water sample to be filtered. In this instructable, I am going to share my simple water filter plan, as well as some helpful hints to assist in your making process.

**Note: This is for entertainment/educational purposes only. It is not intended to be used as a water filtration system for human consumable water sources.

Step 1: Materials + Tools

Tools:

Drill and 1/4" drill bit
Scissors
Box Cutter
2 Liter Bottle (2)
Measuring Cups
Measuring Spoons
Funnel
Colander
Pan 6" X 10"

Materials:

Wash Cloth (1)
Cotton Balls (8)
Coffee Filters (4)
Small Gravel 1/2 cup
Fine Sand 2/3 cup
Charcoal 2/3 cup
Corn Starch 1 Tablespoon
Tea Granules 1 Tablespoon
Potting Soil 1 cup
Water 8 cups

Step 2: Steps to Make the Water Sample

Set a 2-liter bottle into a pan (6" x 10") to catch any spills.

Step 3:

Place a funnel into the top of the 2-liter bottle.

**Note: If the end of the funnel is too narrow, use the box blade or sharp scissors to trim off the bottom of the funnel to make the opening larger.

Step 4:

Measure 1 cup of potting soil.

Step 5:

Pour the potting soil into the funnel.

Step 6:

Measure 1 tablespoon of tea granules.

Step 7:

Add the tea granules to the bottle via the funnel.

Step 8:

Measure 1 tablespoon of cornstarch.

Step 9:

Add the cornstarch to the bottle via the funnel.

Step 10:

Add 8 cups of water to the bottle via the funnel.

Step 11:

Remove the funnel and replace the bottle cap.

Step 12:

Shake the bottled water sample.

Step 13: Steps to Make the Filter

Drill a hole into the 2-litter bottle. (Use the empty bottle)

**Note: Place a block of wood under the bottle cap, so that you do not drill into the tabletop.

Once the hole has been drilled, screw the lid back onto the bottle.

Step 14:

Cut the empty 2-liter bottle into two pieces.

Use the box cutter to start the cut, and then use the scissors to continue cutting the bottle.

The bottom half of the bottle should be cut, so that it is 1" above the half mark. This will cause the bottom part of the bottle to be slightly longer than the top half. You do not want them to be equal in length as the top section will be placed into the bottom section and adequate spacing needs to be available.