A water filter is where you turn dirty water into clean water so first you will need some pebbles cotton balls and sand. First you put in the cotton balls then some sand then the pebbles the pebbles will get out all the big pieces of of dirt then the cotton balls will get out all of the germs in the dirt and the sand will the sand will make the water get through but the sand will absorb the soft dirty thing and the rock absorb hard dirty thing.
