DIY 2-liter Bottle Ecosystem Project

Learn How to Create an ecosystem bottle project

I’m afraid my title, "DIY 2-Liter Bottle Ecosystem Project", will scare off you and the grands. Don't let it! The word “project” sounds like boring work, but this activity is so fun and intriguing.

It is easy to make for your home or could be used for an educational ecosystem science project if desired. Isn’t that a win-win?

So what is an ecosystem anyways?

With a little bit of study, the whole concept of an ecosystem will open your kids’ (and your) eyes to how interconnected our world is! It is amazing how things work together and how we can fit into that interconnectedness. Wow, that is a long word- 18 letters long! 

So, what is an ecosystem? It is the relationships between interacting, dependent organisms and the physical environment that they are in.

Make an aquatic ecosystem in a bottle

Since this project has fish and plants it is called an aquatic ecosystem and you will use goldfish and a couple plants in a 2-liter bottle like you get from soda to make it. The fish provide nutrient rich water for the plants and the plants help oxygenate the water. That being said, since this is such a small ecosystem, you will still need to care for the fish and plant beyond how they work together to feed and water one another. More on that later.

Let’s set up our aquatic ecosystem

The day before you make your DIY 2-Liter Bottle Ecosystem Project, fill a container with water. Let it sit overnight until you use it to fill your bottle. The water needs to sit so that it is room temperature and dechlorinated, ready for the fish.

Recycled pop bottle aquatic ecosystem- yessss...

Grab a 2-Liter bottle out of your recycling bin. Wash and clean it out well. It works best for the 2-Liter bottle to be clear plastic as you can see through it better (obviously, ha).

Cut and trim the bottle

Cut the bottle off about ⅓ of the way down, right before the curve on the neck of the bottle. I used a small utility knife ( Fiskars HD Craft Knife) but a Scissors will work as well. This may require adult help for the smaller grands.

Trim the edges of the bottle so there are no jagged edges that may scratch you.

In the larger bottom section of the 2-Liter bottle, cut a small hole 1 inch down from the top edge to use to feed the fish. This doesn’t need to be a very big hole, just large enough to put a couple flakes of fish food through.

Add decorative fish rock...

Place decorative fish rock (Aquarium Gravel) or other clean rocks in the bottom of the base. This rock layer was about 1.5 inches thick. The rock holds some of the waste so that the water stays cleaner and clearer longer.

...room temperature water...

Add the room temperature water from your container that has been sitting overnight and fill the base to about ¾^th full. 

...and add your fish!

Gently transfer your fish into the base of the 2-Liter bottle. This is a goldfish but other hearty fish, such as a Beta fish would work well too. The goldfish is a very inexpensive option. Ours came from a local pet supply business.

Note: I have two fish in this container, but it is such a small space that one would be a better number.

Next the top section

Take the pop bottle lid off and put two Coffee Filters in the top section of the 2-Liter bottle. Papa didn’t know it, but I used a few more of his Coffee Filters. I need to buy my own to have in my craft supplies as I use them more often than I thought I would.

Note- Some people use a piece of clear plastic instead of coffee filters so they can see better. 

Add a wick- 

To get the water to come up from the fish area and into the plant soil we are going to make a wick. Use a piece of 10 inch long cotton cord or heavy String. Tie a knot in the cord. Pull the cord down through the bottom of the filters and through the opening of the bottle. Coil the top end of the cord so it stays put in the top section of the bottle. It is good if this part can be pulled up into the potting soil in the next step so it can draw water up into the root section of your plant.

Tip: You can cut 6 or 9 pieces of cotton string about 12 inches long and braid them together to make the wick thicker and draw water up better. This is another good lesson, how to braid!

Optional step-

I wanted my top section of the 2-Liter bottle to sit higher up so I cut four small x shaped holes equal distance around the neck of the bottle. I used two wooden skewers to poke through these holes and then broke off the sharp ends of the skewers. This propped and balanced the top section up a couple inches higher. This step is optional. The top section can sit directly down on the bottom section.

Plants and potting soil

Carefully remove your plant(s) from their container and place in the top section of the 2-Liter bottle. Add extra Potting Mix Soil to this section so the soil and plant is almost to the top. 

Any small plant will work, like a philodendron or a flowering plant (think pansy for example). Next time I’m going to try an herb plant. My plants were very small. so I placed two in the top. They will fill out soon!

Place the top section onto the base section with the bottom of the cord dipping into the water.

Eventually the roots of the plants will come down through the hole and into the water but until then the cord will draw the fish nutrient filled water up to the plant. The whole ecosystem works together to survive, in theory it is a self-sustaining ecosystem project.

Care for your DIY 2-Liter Bottle Ecosystem Project

As I mentioned earlier, this is a very small ecosystem so you will need to change the fish water when it gets cloudy with water that has been standing overnight (like we discussed earlier). You may want to water the plants a bit and allow the extra to run down and replenish the fish water occasionally or just add some water to the fish area occasionally if it gets low.

Also it is good to feed the fish according to directions on a Fish Food container. There probably won’t be enough from the plant and algae to provide all the food needed for the fish to live.

Note: You can make this project without the fish and just have a recycled self-watering plant container if you want!

Asking permission first- a good idea

This is a project that requires some follow up care. That is good for developing responsibility and awareness of pet care, but please ask parents if they would like to have an additional pet in the house before sending this project home with their child. That’s only fair! Make it without the fish if they like that option better.

Learning more about ecosystems

Have fun and learn a lot about ecosystems!! There are a lot of books about ecosystems for children if you are interested. I have a couple listed below.

Supplies for DIY 2-Liter Bottle Ecosystem Project

• Container to keep water overnight
• 2-Liter Bottle (like for soda, clear is best- recycle if possible)
• Rock for a fish tank (called Aquarium Gravel or other small, clean rocks)
• Goldfish (or Beta fish)
• Fish Food
• Plant- like a philodendron or violet or an herb
• Potting Mix Soil
• Coffee Filters
• Cording or String
• Scissors or Fiskars HD Craft Knife

More Recycled Material Craft Projects for Kids

Loving getting to use up those recycled materials from around the house? Check out these fun creative ideas to put even more to good crafty use!

• Recycled Plastic Bottle Bird Feeder
• DIY Recycled Tin Can Stilts
• How to Make Recycled Paper at Home
• DIY Recycled Oatmeal Container Gift Box
• Whimsical Repurposed Wind Chimes
• Recycled Milk Jug Ghost Luminaries
• DIY Purse From a Book Cover

Enjoy!

If you try this recipe (especially with the grands), let me know! Go ahead and leave a comment, rate it, and tag a photo with #WelcometoNanas wherever you post.

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