5 Basic Elements of an Alternative Aquarium

Alternative Aquarium
An alternative aquarium can take many different forms; some components are not always necessary or can be exchanged for others. However, by examining five basic elements of an alternative aquarium, we can establish a starting point and begin to understand how aquatic ecosystems function. These elements are: 1) substrate, 2) small organisms living in the substrate, 3) plants, 4) fish, and 5) water.
Substrate: Here, submerged soil is topped with gravel. This basic combination is the easiest to start with, but many others are possible. The gravel keeps the soil from getting stirred up and moved around by the fish and water currents. Small invertebrates also take refuge in the gravel layer.
Small organisms living in the substrate: Worms, invertebrates, and bacteria help keep both the substrate and water in good health. Pictured above are Tubifex worms, a common aquatic worm. Like earthworms, they constantly process earth and detritus to excrete stable, nutrient-rich castings (the small rod-shaped accumulations). Live worms like these are commonly sold as fish food by independent aquarium stores. There are many species found around the world, each with its own requirements, but most can easily be kept in an alternative aquarium (until the fish eat them). They will reproduce if the water temperature is appropriate, if their population density is low, and if they have enough to eat.
Plants: The grass-like leaves of this Sagittaria subulata plant are thin and translucent. Plants help keep the water quality high and provide several other benefits, such as shelter and shade for the fish. Plants can also house and nourish a robust food chain of invertebrates.
Fish: These are most active members of the aquatic habitat. They usually reside at the top of the food chain; however, fishing spiders, fishing snakes, crayfish, and some salamanders will catch and eat fish, given the chance. Incorporating amphibious animals requires creating a combination terrarium and aquarium, sometimes called a paludarium.
Water: There’s more to water than meets the eye. It contains mineral nutrients, acids, and other important compounds as well as microbes that can be either helpful or harmful. This test tube holds a 5 milliliter (mL) sample of aquarium water, ready to be tested.

These five elements are strongly linked to one another, each having an influence on the others.

The fish consume invertebrates, algae, other natural food sources in the aquarium, and any supplemental commercial fish food they receive. Like all animals, fish extract energy from their food (the calories it contains) and release certain waste products resulting from the process. Waste products come in solid and dissolved forms.

Dissolved fish waste is mainly (1) toxic ammonia or related compounds and (2) carbon dioxide (CO2).

Plants and algae rapidly consume ammonia (and related compounds) and CO2 because they need both the nitrogen contained within the ammonia and the carbon contained within the carbon dioxide. Via photosynthesis, they use these and other nutrients to convert light into a solid form of energy, namely sugars, and then other compounds (like fats) through subsequent biological processes. During photosynthesis, plants release their own version of waste ― dissolved oxygen ― into the water. In this way, one organism’s trash is another’s food and air.

The solid fish waste is encapsulated and quite important. Microbes and invertebrates eat it, slowly breaking it down over time. It’s a slow-release fertilizer for the plants and algae and a stable food source for microbes. Stable nutrient sources like this help keep the ecosystem balanced.

Beneficial bacteria also consume ammonia and related compounds. They live on and between the countless tiny surfaces within the substrate and on the many other surfaces of the aquarium.

Some varieties of bacteria, including the beneficial ones, produce toxic nitrite as a waste product. This nitrite, like ammonia, gets consumed as a nutrient source by other varieties of beneficial bacteria and plants. After being consumed, nitrite is processed into various compounds and integrated into the living cells and tissues of the organisms.

Some of the bacteria, after consuming nitrite, release nitrate. Nitrate is relatively harmless in low concentrations, and in turn it is consumed and transformed by other types of bacteria and plants. Plants additionally absorb a wide variety of toxic compounds from the water and soil, locking these substances away inside their tissues.

The substrate is a physical space for the plants to take root and a shelter for small invertebrates and microorganisms. The “soil” layer of the substrate both slowly releases nutrients and slowly absorbs some types of nutrients. In this way, the substrate acts like a rechargeable battery which powers plant growth. “Soil” can mean a lot of different things; here it refers to a soil with a moderate amount of semi-available organic carbon and nitrogen in it, in the form of organic matter, something which will be explained in more detail.

Invertebrates in the substrate churn the soil, helping to keep it aerated, which helps keep it healthy in the context of an aquarium. A balance exists in the soil between oxygen-rich (aerobic) areas near the surface, and oxygen-deprived (anaerobic) areas deeper in the soil. Different bacteria and biological processes occur in each area. Plant roots also alter the chemical and biological activity of the soil by creating little pockets of aerobic soil around each root. Also of note, tiny areas of anaerobic soil automatically develop within aerobic areas, helping to maintain a balance of biological processes.

The water connects all of the other elements of the system. It transports waste products, nutrients, oxygen, and carbon dioxide. But not all water is the same: its mineral content and characteristics such as temperature determine what organisms can thrive in it.

Once these five components interlock, the ecosystem becomes amazingly stable.

Leave a Comment

Your email address will not be published. Required fields are marked *