How to Make a Closed Ecosystem

A closed ecosystem is one that is able to sustain itself. In other words, it has all the components to support life, including organisms and nutrients, and requires no outside input. Building a closed ecosystem requires a balance between biotic factors, such as plants and animals, and abiotic factors, such as air and sunlight.

Difficulty: Moderate

Instructions

Things You'll Need:

• Aquarium
• Large glass jar with tight-fitting lid (at least 1 gallon)
• Aquarium gravel
• Aquatic plants
• Small fish, such as guppies
• Brine shrimp
• Aquatic snails

1. Add a layer of aquarium gravel to the bottom of your glass jar.

2. Fill the jar with water. Either let the jar sit for 24 hours or add anti-chlorine drops to remove the chlorine.

3. Plant your aquatic plants into the gravel layer. Use many plants--these organisms are necessary to oxygenate and remove carbon dioxide from the water.

4. Add a selection of small aquatic organisms, such as brine shrimp, aquatic snails or betta fish (one male).

5. Place the lid on the jar and close it tightly.

6. Keep your closed ecosystem in an area where it receives filtered (that is, not direct) sunlight.

Tips & Warnings

• Though your ecosystem should be self-sustaining, monitor the conditions to determine how the organisms within are doing. You may need to add more plants or animals depending on the conditions and organism survival rates.

References

• Building a Closed Ecosystem
• What Does It Take to Make A Closed Ecosystem?