2026–27 · Main lesson · Fall 2026
Compare Model Filters and Plan for Safe Water
Adult extension of: Water Filter: Water in an Emergency
October 5–8, 2026 · planning reference
Build two small filtration models and compare how they change visible particles. Use the results to distinguish a useful demonstration from an actual safe-drinking-water plan.
Curriculum skill focus: Size discrimination, sequencing, cause and effect, comparing visible change, water safety
01 · Learning
Objectives
- Compare two filter arrangements using the same test-water volume.
- Separate observable clarity from untested safety claims.
- Identify a trusted source of drinking water during an advisory.
02 · Preparation
Materials
Two stable funnels in stands; clear shatter-resistant cups; clean gravel and rinsed sand; coffee filters; clean tap water mixed with a little clean soil for demonstration only; measuring cup; tray; timer; labels; towels; local water-advisory example. Facilitator prepares any cut containers before the session.
03 · Practice
Adult project
- 1
Label every cup and the source jug DEMONSTRATION ONLY — DO NOT DRINK. Agree on observation, pouring, timing, or recording roles and place everything in a spill tray.
- 2
Choose a comparison: the same amounts of sand and gravel in a different order, or paper alone versus paper plus media. Write or select a prediction and identify the single difference.
- 3
Use the same mixed test-water volume for each filter. Pour slowly; record passage time and compare the collected samples against a white background without tasting or smelling them closely.
- 4
Record visible particles, color, and flow in words, marks, photographs of the setup, or a partner-supported chart. Repeat if practical, remixing the source before each equal portion.
- 5
Decide what the test cannot show: clarity does not establish removal of germs or dissolved chemicals. Review an official advisory and identify bottled water or the treatment specifically directed by local officials.
- 6
Create a three-part decision card: check the advisory, use an approved supply, and ask for help when uncertain. Dispose of demonstration water appropriately, clean the station, and wash hands.
Evidence & interpretation
What the investigation shows
Filtration can separate some suspended particles by size. This model neither measures pathogens nor tests dissolved contamination, so its appearance is not a safety test.
Practical connection
Why this work matters
This investigation builds consumer judgment, fair testing, practical recordkeeping, and emergency planning. The useful outcome is knowing when a filter claim needs stronger evidence.
Participation by choice
Individual access options
- Choose a dry role such as timer, label reader, or evidence reviewer; watching is full participation.
- Use a funnel clamp, lightweight measuring cup, seated-height tray, and partner pouring if desired.
- Offer large-print or picture choices for clearer / similar / more particles, with speech, pointing, writing, or AAC responses.
Review & transfer
Reflect on the work
- What evidence would you need before calling water safe to drink?
- Which instruction on a real water advisory would change your usual routine?