Creating an ecosystem inside a bottle is a fun way to understand how plants and animals interact with their environment. You can keep an eye on your own ecosystem and keep track of the changes you notice on a daily basis. To do this, you can try creating a simple plant-based ecosystem, a slightly more complex one based on water and plants, or an aquatic one.
Method 1 of 3: Create a Simple Plant-Based Ecosystem
Step 1. Cut off the top of the bottle
To create an ecosystem in a bottle, you need a 2-quart (2 L) plastic bottle. It is best to use clear plastic so that you can observe what is going on inside. Cut off the top of the bottle, just below the neck.
- To make sure your cut is straight, you can wrap some painter's tape around your neck and use it as a guide for cutting.
- You can use scissors or a utility knife to cut the bottle.
- Save the part you just cut for later use.
Step 2. Add soil to the bottle
Use a small garden shovel to fill 2 to 3 inches (5 to 8 cm) of soil to the bottom of the bottle. Gently press down on the surface with your hand to make it settle. Be careful not to apply too much pressure to avoid compacting the soil.
If you want, you can add a 1/2-inch layer of small pebbles to the bottom of the bottle to improve drainage. You must do this before filling in the soil, but it is optional
Step 3. Create small holes to plant the seeds
The depth of the holes will depend on what type of seed you want to use. Green beans are recommended to start with as they grow fast. Read the instructions on the seed package to find out how deep the holes should be. Then, press down on the ground with a finger or pencil.
- If you are planting beans, the holes should be about 1 inch (2.5 cm) deep.
- Drill the holes near the edge of the bottle. So you can see how the roots grow.
Step 4. Place the seeds in the holes
Once the holes are ready, put a seed in each one. You should be able to place 5 to 6 plants. Then cover the seeds with soil.
In addition to beans, you can plant other types of herbs, such as mint, basil, and oregano
Step 5. Sprinkle grass seeds on top
Take two pinches of grass seed and sprinkle them on the ground. Cover them with a little extra soil. If you want, you can add worms and insects to the ecosystem.
Step 6. Water the seeds
Before sealing the ecosystem, remember that you must water the seeds. Squirt water into the bottle. The idea is that the earth is moist but not soggy or flooded. Allow it to soak up the water, then add a little more liquid. Make sure it permeates all of the soil.
If you tip the bottle and the water runs down the sides, you have put in too much
Step 7. Flip the top over and insert it into the base
Take the part you cut out along with the lid and flip it over. Place it inside the bottle so that the spout is a few inches from the ground.
Step 8. Tape the edges together
Use tape to hold the top in place and seal the ecosystem. This will hold both parts.
You will no longer have to add water to your ecosystem
Step 9. Place the ecosystem where the sun falls
Once it's sealed, put it in a sunny area. For example, a window frame is a good place. Keep in mind that the chosen place should receive sunlight most of the day.
You can also put a label on the bottle with the date and an identification number. In this way, you will be able to keep a record and compare the information with that of other ecosystems
Method 2 of 3: Build a Complex Ecosystem
Step 1. Cut a 2-quart (2 L) bottle just above the base
You can use a utility knife to cut the clear plastic bottle just 1 inch (2.5 cm) from the base. The plastic in this area is usually thicker, making it very difficult to cut with just a pair of scissors.
- You can get rid of the small base, as you will not use it again.
- Store the top with the lid for later use.
Step 2. Cut another 2-quart (2 L) bottle just below the spout
Take another bottle just like it and cut it just below the neck. You can use scissors or a utility knife to do this.
Store both parts of the bottle. The base will be the body of the ecosystem, while the peak will serve to seal it
Step 3. Punch a hole in the top of the first bottle
Take the cap off the first bottle you cut. Place it on a cutting board and clamp it in place with pliers or a hand vise. Carefully drill a hole in the center of the lid.
- If you are a young child, ask an adult to help you drill.
- Wear protective goggles when using the drill.
Step 4. Pass a string or wick through the hole
Pierce the opening with a cotton string or a long piece of wick. You can find the wick at a craft store. You will need 3-4 inches (8-10 cm) for this project.
- Screw the cap back onto the bottle.
- Put this part aside to continue using it later.
Step 5. Pour water into the base
Now you will need the base of the other bottle. Fill it with water. You may have to do several tests to get the exact amount to use. If you add too much water, the lid will be submerged, and if you add too little, the wick will not touch the water.
Step 6. Turn the other bottle upside down inside the base
Make sure the wick is submerged without the lid touching the water. This will help keep the soil moist. In this way, the plants you plant will receive the water.
Step 7. Pour soil into the bottle
Now fill 3-4 inches (8-10 cm) of soil into the bottle. Make sure the wick is completely covered by soil.
Step 8. Sow some seeds
You can plant a wide variety of seeds in your ecosystem. For example, you can use green beans, basil, mint, oregano, peppers, among others. Read the directions on the package to find out exactly how deep the seeds should be. Most of them are placed 2.5 cm (1 inch) deep. Put each variety in its own space and take note of where each one is. This way, you can keep track of them as they grow.
Step 9. Water the seeds
Once you finish sowing, you will need to water them so they can grow. In this ecosystem, they will normally receive water from the base, but it is a good idea to give them some water at the beginning as well.
Step 10. Tape both parts together to seal the ecosystem
Take the last part of the bottles, the spout, and place it over the ecosystem. Tape the edges to seal it and hold it in place. Make sure the cap fits snugly.
Step 11. Place the ecosystem under the sun
Once it's sealed, put it in a place where it gets sunlight. Keep track of what happens each day.
Method 3 of 3: Make an Aquatic Ecosystem
Step 1. Fill the bottle ¾ full with water
Use a 2-quart (2 L) plastic bottle and fill it 3/4 full with water. You can use water from a pond or stream in your area, or simply from the tap at home. It is preferable that they are from natural sources, since this way you will also get aquatic microorganisms.
If you are going to use tap water, be sure to let it sit in an open container for at least 24 hours before using it for your ecosystem. The chlorine in it could kill the plants or animals you put in the bottle
Step 2. Add small stones
Next, add a 1 to 2-inch (2.5 to 5.1 cm) layer of pebbles. It is better to wash them before placing them in the ecosystem. This way you will get rid of any contaminating element.
At this point, you can also add a dead leaf. This serves as food for the microorganisms in the water
Step 3. Set up aquatic plants
You can buy aquatic plants at any pet store. When you put them in the water, be sure to separate them and put them one by one.
Another option is to collect aquatic plants from a natural pond
Step 4. Put snails in the bottle
You can find water snails at a pet store. You can also find them in a pond in your area. Make sure they are small to fit through the opening of the bottle.
Step 5. Wait 24 hours before placing the lid on the ecosystem
Once you finish placing all the desired elements, you will have to wait approximately 24 hours to seal it. This will allow you to settle. After this period, you can screw the cap back on.
Step 6. Put the ecosystem in the sun
Place your aquatic ecosystem in a sunny place. The bottle should receive indirect sunlight throughout the day.