Duration: 45 minutes
SPIRIT Skills:
- Problem-Solving
- Curiosity, sense of wonder and openness
- Creativity
- Flexibility
- Resilience
Brief Description:
In small teams, students plan and build their own water filter system using natural materials. First, they discuss and sketch a plan for the filter: What order will they layer the materials in? Why? They are encouraged to make assumptions about which materials will trap dirt most effectively. Once the plan is agreed upon, they begin constructing the water filter using a cut plastic bottle as the base. The materials they can use include gravel, sand, paper filter or cloth, and activated charcoal. These are placed in different layers inside the bottle. During the process, students are encouraged to make changes if something doesn’t fit or if a new idea arises. The goal is not perfection but experimentation, collaboration, and testing their ideas in practice.
How does this develop particular SPIRIT skills
- Problem-solving: Students take an abstract challenge (dirty water) and work to create a practical solution.
- Creativity: They use everyday materials in novel ways to design an effective filter.
- Resilience: When their first idea doesn’t work, they revise and try again.
- Flexibility: They adapt their approach when outcomes differ from expectations.
- Curiosity, sense of wonder and openness: Students explore how different materials affect water quality and ask questions about the process.
- They practice giving and receiving feedback within their team.
What do we want to achieve regarding SPIRIT skill development (student understanding and/or behaviour)?
- Students are able to describe why they chose a specific sequence of layers in their filter.
- They become more confident in planning and building simple functional models.
- They improve their fine motor skills and develop material sense through hands-on work.
- They learn that testing and redesigning is part of every engineering process.
Academic/Curriculum Objective connection
- Environmental Studies: understanding how filtration works using natural materials
- Science and Engineering: planning, building and testing a simple model
- Mathematics: estimating material quantities, comparing volumes, basic sequencing
- Communication and Collaboration: team discussion, collective problem-solving
Materials and tools needed for implementation
- 1 empty transparent plastic bottle per group (cut open to use as a funnel)
- Filtering materials: fine sand, small and large gravel/pebbles, activated charcoal
- Filtering base: coffee filter, cloth, or paper towel
- Tape, scissors (child-safe), measuring cup, small containers
- Tray or plastic tablecloth to catch spills
- Planning sheet (with blank filter diagram)
- Pencil, crayons for labelling or sketching
- Access to “Material Station” with spare supplies
Preparation notes
- Prepare material kits in advance, one per group, with a backup “material station” for refills.
- Print or draw a filter diagram as a visual planning aid.
- Consider group dynamics: assign flexible roles (e.g., designer, builder, materials manager) to balance participation.
- Allow enough time for construction, and expect some teams to revise mid-process.
- Pre-cut the bottles for safety and time-saving.
- Have paper towels or cloths ready for cleanup
Guided Questions
- Which material do you think will block the most dirt? Why?
- What happens if we put the sand first? Or last?
- How could we stop the small pieces from falling through?
- What order do you think will work best to clean the water?
- If this doesn’t work, what could you change next time?
- How can we make sure the water passes slowly through the filter?
Stage Debriefing Questions (Optional)
- What was your team’s plan, and how did it change during building?
- What did you find difficult about making your filter?
- Did everyone in your group get to help? How?
- What would you do differently if you started again?
- What would you tell another group trying this for the first time?
Tips and Tricks for dealing with stage challenges
- For fast finishers: offer an extra challenge: redesign the filter with one material removed.
- For students who struggle with planning: provide a visual prompt or a “filter sequence” example sheet.
- For dominating team members: assign rotating roles to ensure equal participation.
- For sensitive students: emphasize that no filter is perfect, this is about testing and learning, not competition.
- To keep the classroom clean: use trays or newspapers under each work area and have a cleanup routine planned.