An Aquarium Ecosystem is a Closed Artificial System That Allows Plants and Fish to Interact in a Balanced Way

An aquarium ecosystem is a closed artificial system that houses plants and fish in a way that allows them to interact in a balanced, healthy manner. The virtuous cycles of nutrient recycling and natural predator-prey interaction that occur spontaneously in nature are consciously replicated, enabling the inhabitants to grow and thrive.

An important consideration for any aquarium is water chemistry. The amount of total dissolved solids, or TDS, is one of the most fundamental characteristics that affects water conditions and thus how organisms interact with their environment. Different water types have different solute levels, and each has its own unique set of characteristics and properties. A fish tank may contain freshwater, simulating a lake or river; brackish water, with a salt content in the range of 500 to 30,000 parts per million, simulating an estuary; or marine water, which has a much higher concentration of total dissolved solids, reflecting ocean water.

Water conditions are determined by factors such as the temperature, salinity, pH, and dissolved oxygen (DO). The salinity and dissolved oxygen in an aquarium are the most critical for aquatic animals because they impact basic water chemistry, which in turn affects how organisms interact with their environment.

Another critical aspect of an aquarium ecosystem is the nitrogen cycle. Fish waste and decomposing organic matter like uneaten fish food and dead plant matter release ammonia into the tank. Ammonia is toxic to fish, but nitrifying bacteria that live on/in the filter media and substrate convert it into nitrites. Nitrites are then converted into nitrates by other bacteria. Eventually, nitrates are removed from the aquarium through a process called denitrification in deep sand beds.

A healthy aquarium also requires a suitable light source that provides the proper amount of UV light needed for both plants and fish. Fluorescent lighting is ideal because it provides the right amount of UV needed to stimulate plant growth and make it easier for fish to find their food.

In addition, the amount of carbon dioxide injected into an aquarium must be controlled. Too much CO2 can cause algae to bloom and can be lethal for fish. It is best to inject CO2 only during the day, so that plants can perform photosynthesis and the fish can breathe.

Adding fish to an aquarium creates an additional trophic level that helps to regulate the environment. Some fish eat algae, reducing their numbers and allowing other species to flourish. This helps keep the aquarium stable and self-sustaining.

An aquarium can be a fun and exciting way to teach students about how plants, animals and humans interact with each other and the natural world. A well-established, self-sustaining aquarium can also help reduce the need for frequent and stressful water changes for fish and other aquatic animals. Changing aquarium water too often can cause stress to the fish and cause them to develop a variety of diseases and infections. A self-sustaining aquarium reduces these issues and keeps the fish happy, which makes for a more enjoyable experience for everyone.