Filtration Project

Name of Activity

Filtration Project




Filter, environmental engineering, budget


Building/EDP, Earth Science

Grade Level



2-3 Hours Total

Brief Description

Kids will create a water filter, attempting to make the dirty water given to them as clean as possible.

Lesson Objectives:

-to understand why it is important that our water is filtered

-to understand how different materials filter differently

-Practice testing and prototype building

Materials Needed:

– Dirty water: can use things such as: glitter, dirt, leaves, small sticks, food coloring

– plastic cups

– cotton balls

– uncooked beans

– jelly beans

– gauze

– coffee filters

– any other filter type stuff you feel would be good to include

– 2L plastic bottles (or large cups (clear) and funnels)

– paper

– pencils

Preparation and Set Up:

First you must make your dirty water by mixing together all of your dirty water ingredients. You then separate the top, cone-shaped part of the 2L bottle from the rest of the bottle using a sharp knife. By flipping this severed piece upside down, you create a container and a funnel. Each group receives one of these 2L bottles. Each group also receives a small plastic cup full of dirty testing water. Before any testing begins, your groups should come up with a filter design on their piece of paper (keeping in mind which materials they want to use and how they want their filter to be structured).

Knowledge Background

It’s nice to ask the kids how they think filters work and why it is important for us to have clean water. It’s also nice to give a brief description on how our drinking water actually does get filtered.



Your groups should first design their ideal filter on a piece of paper. Each group then comes up to you with their idea to be “approved”, and you give them the necessary materials. They then build their filter within the funnel and test their filter using their given dirty water. Once their water gets filtered, the students in each group should take notes on the state of the filtered water and what they think worked and what they think didn’t. Students should then redesign and retest to create a better filter.


You can give the students a “budget” so that filtration materials cost a certain amount of money. This, for example, prevents kids from just grabbing twenty cotton balls and shoving them into the funnel and teaches them a little more about the business side of engineering.


-lower the budget each time

Umbrella Unit/Curriculum (if applicable)

Page 1 of 2 | Next page