Build a Mini Oyster Filter

📋 What You'll Need

• •2 clear jars or cups
• •Dirt or sand to muddy the water
• •Live oyster shells (or crushed shell) — make sure they're clean
• •A stick or spoon to stir
• •Water from a tap or hose

👣 Step by Step

1. 1Fill both jars halfway with water.
2. 2Add a spoonful of dirt to each jar and stir until the water is cloudy.
3. 3Leave Jar 1 alone as your 'control' — nothing in it.
4. 4Add a handful of clean oyster shells to Jar 2.
5. 5Set both jars somewhere they won't be disturbed and wait 30–60 minutes.
6. 6Check both jars. Compare how clear the water looks now.
7. 7Take photos at the start and after waiting to see the difference.

🔍 What to Observe

• •Which jar is clearer after waiting?
• •Did the shells catch anything at the bottom?
• •What would happen with more shells, or more time?