ALEX Lesson Plan


Filtered or Not Filtered That's the Question!

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  This lesson provided by:  
Author:Christal Hall
System: Washington County
School: McIntosh Elementary School
Author:Timothy Johnson
System: Mobile County
School: Collins-Rhodes Elementary School
The event this resource created for:NASA
  General Lesson Information  
Lesson Plan ID: 34286


Filtered or Not Filtered That's the Question!


Students will collaborate, design, and construct a device that filters contaminated water. 

This lesson was created as part of the 2016 NASA STEM Standards of Practice Project, a collaboration between the Alabama State Department of Education and NASA Marshall Space Flight Center.

 Associated Standards and Objectives 
Content Standard(s):
SC2015 (2015)
Grade: 5
17 ) Design solutions, test, and revise a process for cleaning a polluted environment (e.g., simulating an oil spill in the ocean or a flood in a city and creating a solution for containment and/or cleanup).*

NAEP Framework
NAEP Statement::
E4.10: The supply of many Earth resources such as fuels, metals, fresh water, and farmland is limited. Humans have devised methods for extending the use of Earth resources through recycling, reuse, and renewal.

NAEP Statement::
E4.11: Humans depend on their natural and constructed environment. Humans change environments in ways that can either be beneficial or detrimental for themselves and other organisms.

Unpacked Content
Scientific And Engineering Practices:
Constructing Explanations and Designing Solutions
Crosscutting Concepts: Systems and System Models
Disciplinary Core Idea: Earth and Human Activity
Evidence Of Student Attainment:
  • Collaboratively design solutions, test, and revise a process for cleaning a polluted environment.
Teacher Vocabulary:
  • Solution
  • Test
  • Revise
  • Polluted
  • Environment
  • Engineer
  • Technology
Students know:
  • Human activities in agriculture, industry, and everyday life can have major effects, both positive and negative, on the land, vegetation, streams, ocean, air, and even outer space.
  • Individuals and communities are doing things to help protect Earth's resources and environments.
  • Research on a problem should be carried out before beginning to design a solution.
  • Testing a solution involves investigating how well it performs under a range of likely conditions.
  • At whatever stage, communicating with peers about proposed solutions is an important part of the design process, and shared ideas can lead to improved designs.
Students are able to:
  • Use grade-appropriate information from research about a given problem, including the causes and effects of the problem and relevant scientific information.
  • Generate at least two possible solutions to the problem based on scientific information and understanding of the problem.
  • Specify how each design solution solves the problem.
  • Share ideas and findings with others about design solutions to generate a variety of possible solutions.
  • Describe the necessary steps for designing a solution to a problem, including conducting research and communicating with others throughout the design process to improve the design [note: emphasis is on what is necessary for designing solutions, not on a step-wise process].
Students understand that:
  • Engineers improve existing technologies or develop new ones to: increase benefits, decrease known risks, and/or meet societal demands.
AMSTI Resources:
AMSTI Module:
Dynamics of Ecosystems

Alabama Alternate Achievement Standards
AAS Standard:
SCI.AAS.5.17- Identify a way humans can prevent or reverse pollution of the environment.

Local/National Standards:

5-ESS3-1.  Obtain and combine information about ways individual communities use science ideas to protect the Earth’s resources and environment.

Cross Cutting Concepts:

Systems and System Models. A system can be described in terms of its components and their interactions. (5-ESS3-1)

Connections to Nature of Science. Science Addresses Questions about the Natural and Material World.

Science findings are limited to questions that can be answered with empirical evidence. (5-ESS3-1)

ELA/Literacy –

RI.5.1 Quote accurately from a text when explaining what the text says explicitly and when drawing inferences from the text. (5-ESS3-1)

RI.5.7 Draw on information from multiple print or digital sources, demonstrating the ability to locate an answer to a question quickly or to solve a problem efficiently. (5-ESS3-1)

RI.5.9 Integrate information from several texts on the same topic in order to write or speak about the subject knowledgeably. (5-ESS3-1)

W.5.8 Recall relevant information from experiences or gather relevant information from print and digital sources; summarize or paraphrase information in notes and finished work, and provide a list of sources. (5-ESS3-1)

W.5.9 Draw evidence from literary or informational texts to support analysis, reflection, and research. (5-ESS3-1)

Mathematics –

MP.2 Reason abstractly and quantitatively. (5-ESS3-1)

MP.4 Model with mathematics. (5-ESS3-1)

Primary Learning Objective(s):

The students will:

• design and build their own water filtering system.

• collect data to compare water before and after filtering.

• develop a conclusion based upon the results of this experiment.

• compare individual results to class results to look for patterns.

Additional Learning Objective(s):



 Preparation Information 

Total Duration:

61 to 90 Minutes

Materials and Resources:

This activity comes form the NASA Education Guide NASA Engineering Design Challenges: Environmental Control and Life Support Systems Water Filtration Challenge.

Materials Needed:

  • safety glasses
  • 2-liter bottles
  • cheesecloth
  • rubber bands
  • pH testing strips (litmus paper)
  • metric rulers
  • plastic cups
  • paper plates
  • metric liquid measuring cups
  • mesh bag (panty hose)
  • tap water or bottled water Italian dressing (to make gray water)
  • aquarium gravel play sand
  • activated carbon/activated charcoal
  • marbles
  • cotton balls
  • coffee filters
  • packing materials (Styrofoam “popcorn”)
  • lima beans (uncooked)
  • paper towels (for clean up and spills)

Gather enough for multiple groups to use 7 different materials for filtration layers

  • aquarium gravel
  • play sand (found at nurseries and home improvement stores)
  • activated carbon / activated charcoal (granules, found with aquarium supplies) Note: Activated charcoal is safe and non-toxic. Be sure to check MSDS.
  • marbles
  • cotton balls
  • coffee filters
  • packing materials (Styrofoam “popcorn”) 

Contaminated Water Ingredients

Instructions for making wastewater can be found on pages 12 and 13 of the Education Guide.  Italian salad dressing could be substituted for the contaminated water as well.

  • vinegar, distilled
  • food coloring
  • sand
  • salt
  • dirt
  • tap water or bottled water

Materials needed per group (3–4 students working together)

  • Water filtration system structure (instructions can be found on page 15 of the Education Guide)
    • 2-liter bottle with bottom cut off
    • cheese cloth
    • rubber bands See how to make the water filtering system structure in the Pre-Lesson Instructions Section.

  •  3 filtration materials (to be chosen during the test procedure)
  •  5 litmus paper strips
  •  pH color chart with a range from at minimum 4-10
  •  1 metric ruler
  •  3 large, clear plastic cups (at least 480 ml.) with a hole punched just below the rim (See diagram in the Pre-Lesson Instructions Section.)
  •  3 paper plates
  •  1 metric liquid measuring cup
  •  500 ml of clean water
  •  500 ml of contaminated water (to be made in advance)

Per student

  •  1 pair of safety glasses
  •  Cleaning Water Student Section


Remind students about the importance of classroom and lab safety. Review the rules for smelling (wafting) in the science lab. Students should wear eye protection during this activity. 

Technology Resources Needed:


At least one day before conducting this experiment:

  • Discuss “purifying and filtering materials” with the class. Encourage students to bring in other materials to add to the list of materials supplied. These will be “free choice” items.
  • Review pH, acid, base and neutral with your students and show them how to pH test using litmus paper. Review the pH color chart.
  • Read NASA’s 21st Century Explorer Web Text Explanation titled “Where Would a Space Explorer Find Water and Oxygen?
  • Read the Observation passage (found in the Attachments section of this lesson plan) to be familiar with the concepts featured in this activity.

Pre-lesson Instructions (30 minutes prep time)

• Students should work in groups of 3 or 4.

• Write the names of the 7 different filtering materials on 7 individual small slips of paper and place them in a hat or basket. In addition, write “free choice” on several small slips of paper. Add enough “free choice” slips for each group to choose a total of 3 filtering materials (suggested option).

You may also place the materials as a "store" and students have a certain price range they can use for the store.

• Gather materials for this activity. Each filtration material needs to fill the water filtering system to a depth of 5–8 cm. There should be enough of each filtration material for several groups to use. Make sure to have extra material for students to chose their “free choice” options.

• Wad up enough coffee filters for multiple groups to use as a filtration layer (You may leave this out and have the filters in the store setting making them develop this strategy on their own).

• Rinse the activated charcoal granules in advance to remove the dust. Put the granules in a mesh bag (panty hoses works well) and rinse with tap water.

Note: To increase rigor, you may give them the contaminated water and bottle filter base. All other materials will be used by each determining group. This allows for higher thinking and creative skills.

Filtering system structure: (one per group)

  • Punch a hole in the top of each cup, just below the rim to avoid a vacuum (optional). * Use diagram in attachment
  • Remove the labels on the 2-liter bottles and then cut off the bottom of the bottle, just above the curve of the bottle.
  • Construct the structure of the water filtering system by covering the mouth of the bottle with at least 10 layers of cheesecloth and secure with a rubber band.

To increase rigor, you may allow the students to determine how to place and use the filter design in their groups independently. 

Make “Contaminated Water”:

  • Test your tap water before making the contaminated water solution. You want to start this solution with “clean water." Your clean water should have a pH between 6.5 and 7.5. If your tap water is not between pH 6.5 and 7.5, then use store-bought drinking water.
  • Mix 1 part Italian salad dressing (vinegar and oil with seasonings, shaken) to 5 parts water in a large, clean container.
  • Make enough contaminated water for each group to have about 500 ml.
  • Note the pH of the contaminated water, it should be around 4. If needed, you can add vinegar to the contaminated water to drop the pH.

Note: Reserve enough clean water (either tap water or store-bought drinking water with a pH between 6.5 and 7.5) so that each student group has about 500 ml. 

Instructional Procedure

1. Show NASA’s 21st Century Explorer Newsbreak video “Where Would a Space Explorer Find Water and Oxygen?” (see right sidebar on website) to engage students and increase student knowledge about this topic.

2. Remind students about pH including base, neutral, and acid. Also reference pH testing using litmus paper and pH color charts.

3. Review the problem with the students.
Problem: What can I do to make clean water?

4. Pass out a copy of Observation and have the students read and discuss in their groups.

5. Encourage your students to discuss and make observations about this topic by completing the first two columns in the KWL (KNOW/WANT TO KNOW/LEARNED) chart in their journals. Use the KWL chart to help students organize prior knowledge, identify interests, and make real-world connections. As students suggest information for the “KNOW” column, ask them to share “How they have come to know this information.”

6. Allow your student groups time to develop a Hypothesis relating to this activity and the “problem question." 

7. Students will test their hypothesis following this procedure.


1. Put on your safety glasses.
(Stress the importance of keeping eye protection on during this lesson.)

2. Place the bottle upside down with its mouth over the clear plastic cup to catch the filtered water.  Make sure the cup underneath the system is large enough to “catch” the water to be filtered through.

3. Choose three slips of paper from the teacher.
Allow each group to choose three slips of paper with designated filtering materials or “free choice” written on them.

The items written on these papers will be the materials you layer in your water filter. If you choose a “free choice” slip, you and your group may choose what material to use for
this filtration layer.


Give students an objective: Their town's water supply is contaminated after a storm. It is their mission to develop a filtration system. The filter must be able to allow water to run through and deposit into the cup. 

Note: This is where you may limit direct instruction and allow creativity. You may also allow the "store" concept to replace the above distribution technique.


4. Gather your filtration materials on the paper plates; one on each plate. As a group, decide the order in which to layer your materials.

5. Fill the bottle with the first filtering material to a depth of 5–8 centimeters (cm).
Note: Coffee filters and cotton balls will need to be packed down.

6. Place the second filtering material to a depth of 5–8 cm on top of the first one.

7. Place the third filtering material to a depth of 5–8 cm on top of the second filtering

8. Obtain 350 ml of clean water. Observe the properties of the water before you filter it. Use the wafting technique to smell the water. Measure the pH of the water with litmus paper and compare it to the pH color chart. Collect data and record your observations. Remember smelling rules in the science lab and do not taste. This pH measurement will serve as the control.


When filtering the contaminated water, students will know the contaminated water is cleaned when it matches the control pH.

9. Run the clean water through your water filtering system to make sure it will allow water to flow through. Students should run approximately 10-16 oz. of clean water through their water filtering system to make sure it will allow water to flow through. Make sure the cup underneath the system is large enough to “catch” all the water passing through.


Allow students to experiment and determine if their design will work.

10. While you are waiting for the clean water to run through the water filtering system, draw and label your diagram to match your filtration system. (this can be skipped and allow students to work without determining if the filter works)

11. Once the clean water has gone through the water filtering system, replace the clear plastic cup with a new one. If the water is sandy, it should be disposed of outside. Otherwise, it can be disposed of in the sink. The cup can be reused in the next step.

12. Get 350 ml of contaminated water. Observe the properties of the water before you filter it. Check the odor of the water. Measure the pH of the water with litmus paper and compare it to the pH color chart. Collect data and record your observations.

Remind students to use the wafting technique to smell the water. They should also measure the pH of this water sample. Go over the rules of the science lab regarding smelling and tasting.

13. Run the contaminated water through your water filtering system. Observe the properties of the water after it has been filtered once and record your observation.

Measure the pH of the water with litmus paper and compare it to the pH color chart. Collect data and record your observations. Remind students the rules of the science lab regarding smelling and tasting.

14. Replace the clear plastic cup with a new one. Pour the filtered water back into the water filtering system.

15. Filter the water again. While the contaminated water is running through the water filtering system, discuss in your group what each layer in your filtration system did to the water.

16. Observe the properties of the water after it has been filtered for the second time. Check the odor of the water. Measure the pH of the water with litmus paper and compare it to the pH color chart. Collect data and record your observations. Remind students the rules of the science lab regarding smelling and tasting.

17. After taking all measurements, study the data and draw conclusions by answering the questions.

Make sure the students compare the properties of their filtered water to the control (clean water) to determine if their contaminated water was “cleaned” by their water filtering system. Using this information, ask students to determine if the data supports or refutes their hypothesis.

18. Dispose of all material by wrapping in newspaper and placing the material in a trash receptacle.

• Discuss the answers to your set questions.
• Have the students update the LEARNED column in their KWL chart.
• Ask students how their findings relate to the development of new water filtration systems and recycling for space exploration?
• Ask students “What do you wonder now?” and encourage students to design their own experiments.

**Some files will display in a new window. Others will prompt you to download.

Assessment Strategies

Assess student knowledge through summative questioning.

 Some sample summative guidelines for questioning:

  • Ask for examples, students talk about outcomes.
  • Summarize what has been said by using the talk moves.
  • Ask students if they agree with statements from peers and have them explain their position.
  • Allow students to discuss the data they have collected. How could this help engineers to develop better ways to filter water?
  • How can data be compared to the other groups?
  • What data supports their outcomes?
  • Ask students about assumptions before, during, and after the activity.

Observe and assess student performance throughout the activity using the attached Scientific Investigation Rubric.

You may also use the activity rubric to grade this activity with or without journal entry.


Collect and filter other samples of water. Examples are rain water, hand wash water, stream or pond water, etc.
• Try using other filter media such as Styrofoam™ pieces, potting soil, marbles, and popped popcorn.
• Have students research how the water in your town is filtered/treated. Maybe take a field trip to the water treatment
plant, or check into having someone from the water treatment plant come to your classroom.
• Because weight is always an issue when launching into space (the heavier it is the more it costs to launch it), set
a weight limit for the filtration device (including filter media). Hold a competition to see which team has the purest
water (lowest conductivity and most neutral pH) using the lightest filtration device.
• If equipment is available, have student teams tape/film their work or take pictures. This can then be used to create
an electronic diary and presentation of their filtration device and results. Have the teams share their creation with
the class.

* Use the Design Evaluation Sheet that includes conductivity 


Students who need extra support should be placed in groups with teammates sensitive to the needs of that student.

The teacher may need to more closely supervise groups that contain students who are struggling with the concepts of this lesson.

View the Special Education resources for instructional guidance in providing modifications and adaptations for students with significant cognitive disabilities who qualify for the Alabama Alternate Assessment.