Layered Water Filter
Sand, gravel and charcoal layers visibly clear muddy water — a model of natural and plant filtration.
Start building ↓The build
Make the funnel
Cut the bottle and invert the top into the base.
Layer the media
Bottom up: cotton, charcoal, fine sand, coarse sand, gravel.
Pour slowly
Trickle muddy water through.
Compare
Hold input and output to the light.
Each layer traps particles by size while charcoal's tiny pores adsorb dissolved colour and odour, so water comes out clearer at each stage.
A closer look
It mirrors water-treatment plants and natural soil filtering. It removes sediment, not germs — never drink the output.
Variables to test
- 1 Remove the charcoal — still clears? Still smells?
- 2 Compare fine vs coarse sand for clarity and speed.
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