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🌿 BiologyHard

Mini Build a Terrarium Ecosystem Challenge

15 minutes 7 materials Ages 7-12

⚠️ Safety Warning

Wash hands after handling soil and charcoal. Be careful with glass jars.

All experiments require adult supervision.

Materials You'll Need

Gather these 7 items before starting

💡 Clear glass works best so you can observe changes.
💡 Any small rocks or pebbles work.
💡 Make sure this item is clean and ready before starting.
💡 Vegetable or cooking oil is perfect for this.
💡 Any small houseplant or seedling.
💡 An empty plastic bottle - clean and dry.
💡 Make sure this item is clean and ready before starting.

💡 Tip: Check off items as you gather them to stay organized!

Step-by-Step Instructions

Follow these 8 steps carefully

1

clean the glass jar thoroughly and let it dry.

🧻Tip: Make sure everything is completely dry before moving to the next step.
2

Add a 2cm layer of small rocks at the bottom for drainage.

3

Add a thin layer of activated charcoal on top of the rocks — this filters the air.

4

Add 5-7cm of potting soil on top of the charcoal layer.

⭐Info: You're doing great! Keep following the steps carefully.
5

Use a spoon to dig small holes and plant your small plants and moss.

6

Mist everything with the spray bottle until the soil is damp but not soggy.

7

Add decorative stones or small figurines if desired.

⭐Info: You're doing great! Keep following the steps carefully.
8

Seal the lid and place in indirect sunlight. Your mini ecosystem is alive!

🛡️Tip: A good seal prevents spills and keeps your experiment contained.

✅ Remember: Take your time with each step and ask an adult for help if needed!

The Science Behind It 🔬

A terrarium is a miniature ecosystem that demonstrates the water cycle! Plants absorb water from the soil through their roots and release it through their leaves (transpiration). This water vapor condenses on the glass walls and lid, then drips back down into the soil — just like rain! The plants also photosynthesize, taking in carbon dioxide and releasing oxygen during the day. The charcoal filters out toxins and prevents mold. A well-balanced terrarium can sustain itself for years without opening, proving how elegantly nature recycles resources! This concept connects to many other areas of science, including astronomy, medicine, and environmental science.

Grade Levels

2nd Grade3rd Grade4th Grade5th Grade

Materials

Large glass jar with lidSmall rocksActivated charcoalPotting soilSmall plants (ferns, moss)