Step 1: Materials
You need Sand, Gravel, Rocks, A Coffee Filter,
A Water Bottle, Scissors, Dirty Water.
Step 2: Instructions 1
Have an adult cut the bottom off a water bottle and poke a hole in the lid.
Step 3: Instructions 2
Place the coffee filter into the bottle.
Step 4: Instructions 3
Put the bottle lid-down into another cup or bottle, leaving room for filters water.
Step 5: Instructions 4
Carefully pour some sand, then gravel, then rocks int the cup. Once that's done pour in some dirty water.
Step 6: Outcome
The dirty water will be cleaned and pour into the bottom.