Creating a self-contained and self-supporting enclosed ecosystem is a project that is quick to set up and maintenance free, and can be beautiful as well as functional.
Pet stores often sell closed aquatic environments with advertising that states they require no food and no cleaning. They come in sizes as small as a tiny glass jar to as large as one or two gallons. They are self-sustaining because they have all the components required for a living ecosystem in the container.
Understanding the Components of an Ecosystem
All ecosystems, whether they are on land or are water based, require three basic components:
Producers
Consumers
Decomposers
Simply put, the producers are the plants, so named because they produce their own food and are the base of the food web. They also produce oxygen, essential for the consumers.
Consumers are the animals and living organisms that feed off the producers, so named because they consume things in the environment. Consumers also contribute carbon dioxide and waste to the ecosystem.
Decomposers are the garbage cleaners of the ecosystem because they recycle the waste products. Decomposers include bacteria and worms. In a water system, snails and ghost shrimp are decomposers.
Producers, consumers, and decomposers must all remain in balance for the ecosystem to thrive. Too much of one of these will result in disaster. For example, if there are too many fish and not enough plants, the fish will starve or will suffocate from lack of oxygen. Therefore, it is important not to overcrowd the environment.
Choosing the Items for the Environment
To create a one-gallon aquatic system, at least two fast growing aquatic plants are needed. Elodea grows well in filtered sunlight, and is excellent food for small freshwater fish. Fish suitable for this type of biosphere are tetras and other livebearers. One large snail or several small snails will keep the environment clean. Snails multiply quickly, but the fish will eat the snail eggs they find.
Putting the Biosphere Together
Choose a one-gallon glass jar or clear plastic container that has a tight fitting lid.
Cover the bottom of the container with aquatic gravel.
Fill the container with filtered water, and let it sit for at least 24 hours. This waiting period allows chlorine to dissipate from the water.
Add any decorative aquarium items desired to give it an appealing look.
Plant the aquarium plants in the gravel.
Before adding the freshwater fish, snails, or shrimp, allow them to acclimate to the water temperature by floating the plastic bag the pet store provided on the surface of the water for a few hours.
Once the water temperatures are equalized, the fish, snails, or shrimp may be introduced into the biosphere.
Close the lid tightly to prevent evaporation.
Place the ecosystem in a location that has filtered sunlight.
Troubleshooting the Aquatic Ecosystem
If algae begins to grow in the container, it may need more decomposers.
If too many decomposers are in the system, the water may become cloudy. Add more plants to provide food and oxygen.
If fish are dying, add more plants.
This project is perfect for a trouble free aquarium in the home. It also makes an excellent addition to the classroom as a teaching aid for biology concepts in the elementary grades. However it is used, it can be beautiful and functional, a natural self-sustaining system in a custom aquarium.
The copyright of the article Creating a Closed Aquatic Ecosystem in Aquariums is owned by Suzanne Pitner. Permission to republish Creating a Closed Aquatic Ecosystem in print or online must be granted by the author in writing.
Can you put some small fish in it, if you can, which fish would be most suitable?
Aug 23, 2009 4:16 PM
Suzanne Pitner :
Thanks for the question! Yes, I always put a few small fish. My current
aquatic system (the one pictured in the article,) has four neon tetras, two
ghost shrimp, and one large snail, along with several tiny snails that were
stowaways on the aquatic plants. I wouldn't recommend more than four fish.
I've also had small danios in these systems. The fish usually live a year
or a bit longer.
Sep 8, 2009 8:08 PM
Guest :
do you need to feed the fish everyday, or can the ecosystem remaine close,
and sustain itself?
Sep 9, 2009 6:09 PM
Suzanne Pitner :
You never need to feed the fish, as long as the ecosystem stays in balance.
That means that you have plenty of plants, enough snails to keep the algae
under control, and not too many fish. I've had my current system going for
over a year now, and we had another one that lasted two years before I gave
it to a student to take home.
Sep 10, 2009 6:26 AM
Guest :
We are making a closed ecosystem in science class that is aquatic. We are
building it in a 2 litter bottle. We recieve one goldfish and any other
supplies that can be found in a nature ecosystem. Would our ecosystem be
successful with only one fish? If so, would you please tell me what to put
into my ecosystem. Thank you very much, you are such a help. :)
Sep 10, 2009 7:25 PM
Suzanne Pitner :
I'm not sure how successful it will be with a goldfish. I've always used
the smaller species such as danios or tetras. With something as large as a
goldfish, you may not have enough oxygen or decomposers to accommodate it
in a 2 liter bottle.
Sep 30, 2009 7:11 AM
Guest :
ok question what plants would you put in to sustain 4 small water snails 2
ghost shrimp 2 neon tetras and 2 small danios? ive been trying to conduct
an ecosytem to be self manageing ,yet can not find the right amount of
plant life any suggestions?
Oct 1, 2009 12:27 AM
Suzanne Pitner :
I have always used elodea with success. It is fast growing and will grow
even in low light conditions. My classroom gets very little sunlight, and
it grows well if the aquarium is close to the window. I start with 2 elodea
plants in a 2 gallon aquarium, and they quickly grow to provide plenty of
cover and oxygen.
Oct 2, 2009 2:41 AM
Guest :
Can you have too many plants in your eco system?
Oct 5, 2009 7:08 AM
Guest :
thx Suzanne for the suggestion of elodea plants it helped alot =-) its now
been sustaining for 4 days and i believe its because of the Eloddea plants
Oct 25, 2009 4:01 PM
Guest :
Is it possible to do something like this in a larger environment? Like a
ten gallon tank? And does outside air hurt the process?
Oct 25, 2009 4:06 PM
Guest :
Can you use algae-eating cat fish like otocinculous instead of snails?
Oct 26, 2009 5:47 AM
Suzanne Pitner :
It should work in any size environment. You just need to adjust the amount
of producers, consumers, and decomposers to maintain the balance.
Oct 26, 2009 5:48 AM
Suzanne Pitner :
I've never tried this with the algae eating catfish. If you try it, leave a
comment to let everyone know how it turns out. Thanks!
Jun 5, 2009
