Eco System Activity – Re-Play

This is our fourth week of our National Craft Month series. Today's craft is learning how to build your very own ecosystem!

Tools needed:
- Three 2-liter bottles
- Aquarium gravel
- Aquarium dechlorinating drops
- Freshwater aquarium plant life (such as anachris or elodea)
- Freshwater aquatic life (snails work, but we used a Betta fish per the pet store employee's recommendation)
- Piece of mesh fabric (I used a pair of tights from the dollar store)
- Rubber band
- Earthworms
- Potting soil
- Clear packing tape
- Sprouting seeds (we used mustard seed but alfalfa or grass seed also work)

1. On the first 2-liter bottle, cut the bottom piece off and set it aside for later use. On the second 2-liter bottle, cut the top spout off. On the third, cut both the top spout and bottom portion of the bottle off -- this will be your coupler piece to connect the other two bottles.

2. Take the bottle you removed the top spout from and fill with a few inches of aquarium gravel. Fill with room temperature water and add 3-4 drops of dechlorinator. Add your plant and make sure the roots are tucked nicely underneath some of the gravel. Add your aquatic life, such as your freshwater snails or Betta fish.

3. Now take the bottle you removed the bottom portion from. Keep the pour spout facing down -- the top will be the open bottom of the bottle. Take a small square of your mesh fabric and secure it over the pour spout opening using a rubberband. Add a slight layer of gravel to serve as drainage. Add some potting soil and then 2-3 earthworms. Add more potting soil over the top of the earthworms and sprinkle some seeds. Push seeds gently into the soil and give the soil a quick spray with water. If you see any dead leaves outside, feel free to add these to the top of your soil.

4. Take the coupler piece -- the bottle you removed the top and bottom from -- and place it just slightly over the bottle with the aquatic life. Use clear packing tape to ensure it's attached sturdily. Place your earthworm bottle into the top of the coupler and tape the two together as well. Take the bottom piece that you had cut from the bottle and set aside, and reattach it to the top bottle using clear packing tape.

5. You now have your self sustaining ecosystem! Keep your ecosystem near a sunny window (but not right on the windowsill -- your fish won't appreciate harsh direct sunlight!) and your seeds should begin to sprout in 3-4 days. The water in your aquatic life bottle will evaporate up and then rain down onto the earthworm level. The seeds will begin to sprout from the rain that falls onto the dirt level and the clean water is circulated back down to your fish!

This was a fun science experiment that Ethan (age 3 1/2) and my sister (age 18) both enjoyed doing. It is a great lesson to teach children about the ecosystem and the life cycle and Ethan has enjoyed waking up each morning to see nature at work! The earthworms and Betta fish -- which Ethan has named 99 Red Balloons -- are welcomed new additions to our little family!





They are fish… they don’t do happy. Fish do healthy, sick, or dead. C’mon people! Great project!

As a side note, as humans we sometimes try to project human emotions on other organisms. While some organisms have similar emotions none have the same emotions as humans. Fish certainly don’t even have similar emotions. Their neurological systems are wired for simple responses to their environments, not complex emotional thinking such as “happy.”

Ignorance is abounding!

P.S. Feel free to respond and call me ignorant, but I will not be checking back so you will be responding to someone else.

Apr 12, 2016


I agree, that poor fish!! Just because it can survive doesn’t mean it is happy or thriving. It’s very cruel and mean to keep any living thing in a container that small. Those fish need a certain temperature and ph and all kinds of things just to keep him from suffering. I’m sorry but I think this is a very bad thing to teach kids!

Apr 19, 2015

Re-Play Recycled:

Dear Charity,
Thank you for the feedback.

Apr 17, 2015


Interesting project, but the poor fish! No room to swim, no food, and no fresh oxygen, plus the stress from fluctuating temps caused by being near a window? I wouldn’t have put even a snail through that.

Mar 30, 2015

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