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How to Cycle Your Saltwater Aquarium for a Healthy Ecosystem

saltwater aquarium cycle

A saltwater aquarium is a unique and fascinating way to bring the beauty of the ocean into your home. With a wide variety of fish, corals, invertebrates, and other aquatic life available for purchase, you can create an exciting and vibrant underwater world. Saltwater aquariums require careful maintenance to ensure the health of their inhabitants but with proper care, they can be a rewarding and enjoyable hobby for years to come.

Our Aquarium is alive

Initially, we must comprehend that our aquarium is a living system. It is not obligatory to have fish or corals in it to sustain life. When we introduce live rock or sand to the bottom, life begins in the aquarium, though it may not be visible to the naked eye. From this point, the aquarium begins to function and support life. However, the life that occurs within it requires our assistance to maintain its stability and health. Therefore, it is necessary to create a food chain. A food web is a complex network of organisms that interact with each other in order to obtain energy and nutrients. It explains the relation ship between different species in an ecosystem and how they are interconnected. By understanding how the food web works in an aquarium, we can create a healthy environment that supports all its inhabitants.

Nitrogen cycle in an aquarium

Live Rock as a filter

Live rock is an essential part of any successful marine aquarium. It is a type of rock that has been harvested from the ocean and is used in marine aquariums. It provides a home for beneficial bacteria and also helps to maintain the oxigen and nitrogen cycle. Live rock is not only aesthetically pleasing, but it also helps to create a healthy environment for all the aquatic life in the tank. When we use live rock to start our project, what we are doing is adding a filter with nitrifying and denitrifying capabilities, capabilities necessary to carry out the implementation of the trophic (or food) web. After introducing the live rock into our aquarium for the first time, the organic matter contained inside will begin to decompose, generating ammonia, which will cause the growth of nitrifying bacteria, thus releasing nitrite and nitrate.Our aquarium then begins to carry out the Nitrogen Cycle. This is what we popularly call aquarium cycling. It is important not to make water changes during this process as we may interrupt it. On the other hand, it is advisable to take water samples for analysis and parameters monitoring thus be aware of the evolution.

Nitrogen cycle in an aquarium


The usual order of events over time

During the initial months of the aquarium’s operation, undesired algae tend to emerge on the surface of rocks, sediments, and crystals. The typical sequence of occurrence includes diatoms, cyanobacteria, filamentous algae, and ultimately coralline algae.

Nitrogen cycle in an aquarium

Diatoms
 are microscopic, single-celled algae that are an essential part of a healthy saltwater aquarium ecosystem. They are often the first typeof algae to appear in a newly established saltwater aquarium and can be quite abundant during the initial cycling phase.While many aquarists consider diatoms to be unsightly, they play a crucial role in the aquarium’s natural nitrogen cycle. Diatoms are photosynthetic, and they use light energy to convert carbon dioxide into organic compounds. During this process, they also release oxygen into the water, which is essential for the aquarium’s inhabitants.

In addition to their role in the nitrogen cycle, diatoms also provide a food source for many saltwater aquarium inhabitants. For example, some species of snails and hermit crabs feed on diatoms, helping to keep their populations in check.

However, excessive diatom growth can be a sign of an imbalance in the aquarium’s nutrient levels. High levels of silicates and phosphates can contribute to diatom blooms, as can excess lighting. Aquarists can take steps to reduce diatom growth by reducing lighting levels or performing more frequent water changes to remove excess nutrients.

In conclusion, while diatoms may not be the most attractive part of a saltwater aquarium, they play a vital role in maintaining a healthy ecosystem.As such, aquarists should strive to strike a balance between controlling diatom growth and ensuring that they continue to play their essential role in the aquarium.

Cyanobacteria are a type of bacteria that can be found in saltwater aquariums. They are often referred to as ‘blue-green algae’ due to their blue-green color. Cyanobacteria are beneficial for the health of an aquarium as they help to keep the water clean and provide oxygen for fish and other aquatic animals. Although cyanobacteria is often present in the initial stages of an aquarium’s life, if not properly addressed, it can rapidly become a bother some and perilous issue for the aquarium’s inhabitants. It is important to monitor levels of cyanobacteria in an aquarium and take steps to reduce or eliminate them if necessary.

One of the main causes of cyanobacteria growth is an excess of nutrients in the water. This can be caused by overfeeding your fish, inadequate filtration, or a buildup of organic waste in the tank. When there is an excess of nutrients, cyanobacteria can quickly take advantage of the situation and begin to grow rapidly. Additionally, poor water circulation can create areas of stagnant water where cyanobacteria can thrive.

Filamentous algae, also known as hair algae, are a type of algae that can grow in saltwater aquariums. They are usually green, but they can also be brown or red.Filamentous algae grow in long, stringy strands that can attach to rocks, sand, and other surfaces in your aquarium. They can quickly take over your tank if left unchecked.

One of the main issues with filamentous algae is that it can block the flow of water and inhibit the growth of other organisms in your aquarium. It can also release toxins that are harmful to other marine life in your tank. So, even though it’s a normal part of the initial phases of setting up your aquarium, you must be cautious and prevent their overgrowth.

Coralline algae are a type of red algae that grow naturally in saltwater environments. They are usually found on rocks, shells, and even the glass walls of your aquarium.Coraline algae come in various colors, from pink to purple and even red. They are known for their hard, crusty texture, which adds a natural touch to your aquarium. Aside from their aesthetic appeal, coraline algae play a crucial role in the health of your aquarium. They help maintain healthy water parameters by absorbing excess nutrients like nitrates and phosphates. Coraline algae also provide a natural food source for certain marine animals, such as snails and hermit crabs. Additionally, their hard, crusty texture can provide a natural hiding place for small fish and invertebrates.

Your aquarium’s coraline algae growth is an excellent indicator of the health of your saltwater aquarium. The growth rate of these beautiful and beneficial algae can let you know if everything is runnings moothly or if you need to make some adjustments.

In the early stages of an aquarium, there is ample space for various organisms to occupy. However, there is competition amongst different species for resources such as light and nutrients, which determines which organisms will thrive at any given moment. After a few months, the introduction of life leads to competition and cooperation among the colonizing organisms, eventually resulting in a stable ecosystem within our aquarium project.

After about a year, when the maturation period is over, the system reaches a state of balance. This means that there are many different types of bacteria and other tiny organisms present which help to maintain the system’s stability.

Don’t panic if you come across some undesired elements in your aquarium a few days after setting it up. It’s all part of the process. We encourage you to keep learning about the captivating world of marine aquariums.

About the author

Picture of Ana M. López

Ana M. López

Ana holds a degree in Marine Sciences and has completed a Master's Program in Aquaculture with a specialization in ornamental species. Additionally, Ana is a certified Dive Master and Cave Diver, taking her passion for marine life to new depths. Ana has gained years of experience in the aquarium industry.