A closed aquatic ecosystem is the same as an aquarium, but the place is closed from the outside world so that the life needs needed by plants and animals must be met in the system. Most species suitable for such systems are usually not very large or colorful. Therefore, if you want to have an ecosystem filled with different types of fish and plants, you can use a regular aquarium. However, read this article if you want to create a maintenance-free aquatic world that can last for months or even years!
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Part 1 of 3: Getting the Right Materials, Plants and Animals for the Ecosystem
Step 1. Decide how self-sufficient the ecosystem will be
The more closed the aquatic ecosystem from the outside world, the more difficult it is to create an independent ecosystem
- An airtight system is a system that is completely closed from the outside world. The plants and animals in them must be small and few in number in order to survive.
- The closed system allows gas and air exchange (for example, through a sponge in the inlet). The gas exchange helps regulate the pH level in the water and allows the release of nitrogen and the entry of carbon dioxide, making the system easier to maintain.
- Semi-closed systems require some maintenance. All closed systems will eventually fail. You can maintain your system longer by changing 50% of the water every month. This can get rid of dirt and add food ingredients. Change the water more often if the system is running low.
Step 2. Decide whether you want to have a freshwater or saltwater system
Freshwater systems are considered easier to build and maintain. Seawater systems are considered less stable, but can be filled with more interesting animal life, such as starfish and anemones.
Step 3. Find a glass or plastic container to house the ecosystem
You can use a jar, 2 liter plastic bottle, cookie holder or 11.3-18.9 L basket jar. However, the smaller system sizes are usually easier to maintain for beginners.
Find a container with a tight-fitting lid for a closed system. Try covering the inlet with cheesecloth or applying a sponge for a closed system
Step 4. Find a substrate for the plant to grow on
You can buy substrate at the store or get mud from a pond (which has the advantage of already containing the small creatures needed in the system). Try adding sand on top of the mud or substrate to make the water clearer.
Step 5. Buy aquatic pebbles or take pebbles from the pond
The gravel layer will provide a surface for microbial creatures and also act as a filter by trapping particles underwater through the gravel due to gravity.
Step 6. Use filtered water, pond water or aquarium water
Aquarium water or pool water is preferable because it contains the bacteria the system needs. If you are using filtered water, you will need to let it sit for 24-72 hours for the chlorine to dissipate.
Step 7. Choose plants or algae
Plants provide food and oxygen for the ecosystem. You need to choose plants or algae that are durable and fast growing. You can pick them up from the pool or buy them. Some of the plants to choose from include:
- Horn moss (freshwater) – Very durable. Requires sufficient light.
- Pond grass or elodea (freshwater) – Long lasting. Needs a little light.
- Willow moss (freshwater) – Slightly less durable. Tends to be suitable at cooler temperatures.
- Bubble grass (freshwater) – Brittle.
- Caulerpa algae (seawater) – Long-lasting to pests.
- Chain algae (seawater) – Requires high levels of calcium.
- Algae valonia (seawater) – Long lasting to become pests.
Step 8. Select the desired animal
Animals eat algae and other waste substances, thereby keeping the ecosystem clean. These animals also produce the carbon dioxide that plants need to survive. Start by including one or two fairly large animals, or 10-20 hyalella shrimp. WARNING: Fish are not suitable for closed ecosystems. The fish will die in it. The following is a list of animals that are more suitable for use:
- Cherry Shrimp (freshwater).
- Malaysian snail (fresh water).
- Hyalella prawns (fresh/marine, depending on the species).
- Copepods (freshwater / marine, depending on the species).
- Starfish Asterina (sea water).
- Aiptasia sea anemone (sea water).
Part 2 of 3: Creating an Aquatic Ecosystem
Step 1. Add substrate (soil) at the bottom of the container
If you're using a container with a narrow inlet, try using a funnel to keep it organized.
Step 2. Plant the plant in the substrate
If the plant floats after being filled with water, try placing more sand and gravel on top of the plant to keep it anchored.
Step 3. Add sand then gravel
Cover the entire soil, but don't hit the plants. Substrate, sand and gravel should fill about 10-25% of the height of the container.
Step 4. Add water
Remember, if you use filtered water, be sure to leave it for 24-72 hours to allow the chlorine to dissipate. The water should be filled to 50-75% of the height of the container. Leave as high as 10-25% space for air.
Step 5. Enter the animal
Before putting them in, allow the animals to acclimate to the temperature of the water by floating the plastic bag containing the animal on the surface of the water for a few hours. Remember, start with one or two shrimp or snails, or 10-20 hyalella shrimp. Ecosystems will die if they are filled with too many animals.
Step 6. Seal the container
Use the screw on the stopper or prop to seal the container. However, you can also use plastic wrap and rubber tape if that's all you have. For closed containers (which allow for air exchange), try using cheesecloth or a gauze sponge.
Step 7. Place the ecosystem in filtered sunlight
Place it near a window, but avoid direct sunlight for hours because it can cause temperature fluctuations that can kill snails or shrimp. Shrimp, copepods and snails are well suited for living in temperatures between 20°C and 27. 8°C. The container should feel cool, but not cold to the touch.
Part 3 of 3: Caring for Aquatic Ecosystems
Step 1. Take a good look at the ecosystem during the first weeks to make sure it is in the right place
Too much or too little sunlight can kill your ecosystem.
- If the plant looks unhealthy, try adding more sun exposure.
- If the water looks condensed or dirty, try adding more sun exposure.
- If algae or shrimp die on hot days, try to reduce sun exposure.
- Note that you may need to move the ecosystem as the seasons change.
Step 2. Adjust the number of animals and plants needed after the first weeks
This is considered important to keep the ecosystem healthy, because you may not find a balance at first.
- Add another snail or shrimp if algae grows. It's important to keep algae under control. Otherwise, algae can cover the walls of the container, blocking sun exposure and killing the ecosystem.
- If the water condenses, it means that there are too many shrimp or snails in it. Try including more herbs.
- If the animals inside are limp, try adding more plants.
Step 3. Know when the ecosystem ends
There's no point in saving the ecosystem after it fails, especially since the ecosystem will start to smell bad. The following are signs that you need to empty the ecosystem and try again:
- An unpleasant or sulfur-like odor.
- Growth of whitish strands of bacteria.
- There are few or no living animals.
- Most plants die.
