How To Cycle A Tank In 24 Hours? | Aquarium Nitrogen Cycle

Last updated on December 24th, 2022 at 11:05 am

It’s important to know that How To Cycle A Tank In 24 Hours for those who plan to set up an aquarium with fish at home. After all, it is an important condition for the development of the correct balance and biofiltration in aqua. In the article, we will not present complex formulas and difficult to remember terms that occur in the process. Let’s try to explain everything in an accessible and understandable language.

How To Cycle A Tank In 24 Hours

The Nitrogen Cycle of a Tank In 24 Hours

Every aquarist should create a balance in the jar so that nitrogen present in the aquarium in the form of ammonia (NH3) and phosphorus, which gets along with food for aquatic organisms, are consumed by plants, and excess organic matter and nitrates (NO3) is removed from the aqua with weeding and water changes. If the ecosystem of the aquarium is unable to process nutrients, then there is an excess of organic matter, nitrates, and phosphates. That is, an imbalance of NPK arises and algae begin to dominate in the bank: Vietnamese, black beard, xenococcus, filamentous.

To remove ammonia (NH3) from water, good biological filtration is necessary, as well as the right substrate in which nitrifying bacteria will grow. To understand how ammonia (NH3) decomposes and how biological filtration occurs, you need to know what the nitrogen cycle is.

The nitrogen cycle is the cycle of ammonia, nitrite and nitrate in an aquarium. It is called nitrogen because there is nitrogen in all the elements participating in the cycle. All the contents of the jar are involved in the cycle: plants, fish, beneficial bacteria that are invisible to our eyes, shrimp.

Due to the presence of food residues in the water, rotting leaves of plants, waste products of aquatic organisms, the content of toxic ammonium and ammonia (NH3) increases in water. Under natural conditions, so that the fish are not poisoned or die, ammonium and ammonia are decomposed by special bacteria into safer nitrite, and after a while into nitrate. This process is called nitrification. There is another process – this is denitrification – this is the conversion of nitrate by bacteria into nitrite and nitrogen gas (N2).

aquarium nitrogen cycle

Nitrification. Conversion: Ammonia Nitrite Nitrate

Now let’s take a closer look at what happens during the nitrogen cycle with ammonia, nitrite and nitrate.

1. Ammonia (NH3 / NH4)

All aquariums contain organic matter. They enter the water with food, waste products of living creatures, rotting leaves of plants. These substances decompose into ionized ammonium (NH4) and non-ionized ammonia (NH3). For the inhabitants of the aquarium, ammonium is not harmful, but ammonia is toxic.

First stage of nitrification. Ammonia  Nitrite.

The first stage involves nitrifying bacteria (Nitrosomonas bacteria). They convert ammonia into nitrite (NO2), appear naturally, and live in soil and filter media.

To process ammonia into nitrate faster, you need to take care of the following points:

  • The number of bacteria must be large. They live on the surface of filter materials, that is, the filter sponge will become the home of only a small part of the necessary bacteria. Therefore, it is better to use an external filter with special bio-fillers. The surface area of ​​the filler is larger than that of a sponge.
  • Good water circulation. The volume of water pumped by the filter should be higher than 3 volumes of water per hour, if more, then this is even better.
  • There must be enough oxygen in the water.
  • Comfortable water temperature 25-30 degrees.
  • When changing the water, make sure that the water temperature does not drop by more than 2 degrees. A sharp change in temperature leads to disruption of the nitrification process.
  • The pH of the water should fluctuate between 6.5-8.5.

2. Nitrite (NO2)

Nitrite is not as poisonous as ammonia, but it also has a negative effect on aquatic organisms.

Second stage of nitrification. Nitrite  Nitrate

Nitrite is processed by the nitrifying bacteria Nitrobacter. After processing, nitrite is converted into the end product of the nitrogen cycle – nitrate (NO3).

Nitrobacter is pickier than Nitrosomonas. Rinsing sponges and bio-fillers under running water, large water changes in the jar, the use of drugs, high ammonia concentrations inhibit the activity of Nitrobacter. This increases the concentration of nitrite in the aquarium, which negatively affects the well-being of the fish.

If the nitrification process goes well in the aquarium, then the nitrite and ammonia tests will show zero.

The Nitrogen Cycle of a Tank In 24 Hours

3. Nitrate (NO3)

For aqua inhabitants, nitrates become dangerous only if they exceed 50 mg / l. To prevent this, you must regularly change the water.

Nitrates are an excellent source of macronutrients for aquarium plants. In herbalists, living plants are happy to consume nitrates.

As you can see, the nitrogen cycle is the process by which the biological system is freed of toxic nitrogen-based compounds.

Related : Start Your First Fish Tank, But How? | Beginner’s Guide

Denitrification. Conversion: Nitrate  Nitrogen gas

In addition to the bacteria described above, there are other bacteria in the aqua. These are aerobic and anaerobic bacteria. Let’s consider each group in more detail.

Aerobic bacteria live in the top of the soil. They need oxygen for their existence. Aerobic bacteria convert ammonium into nitrates. The soil area in the jar is small, so bacteria settle in bio-fillers.

Anaerobic bacteria live in the middle and lower soil layers. They do not need oxygen; they are necessary for the conversion of nitrate into nitrogen. This process does not take place in aquariums with internal filters and canister filters, as oxygen is constantly present there. Nowadays, specialized stores sell external denitrifying filters. But aquarists use these very rarely.

In the first chain of the nitrogen cycle, nitrate is not the final decomposition product of ammonia. It helps nitrifying and anaerobic bacteria get oxygen.

In the picture below, you can see how the nitrogen cycle occurs in the aquarium.

take proper care of and aquarium

How Long Does It Take To Establish A Nitrogen Cycle In a Freshly Started Aquarium?

It takes 4 to 6 weeks to establish the nitrogen cycle. It is enough time for ammonia to convert into nitrate. Below is a diagram of the maturation of the nitrogen cycle in a new jar.

How Long Does It Take To Establish A Nitrogen Cycle In a Freshly Started Aquarium

In conclusion, I would like to say the following. The words “starting the aquarium” and “establishing biological equilibrium” are all the same and mean the establishment of the nitrogen cycle. To avoid a breakdown in the balance, you need to follow simple rules:

  • Don’t overpopulate your aquarium.
  • Install a good filter.
  • Don’t overfeed your fish.
  • Siphon the soil regularly and change the water.
  • Use chemicals and medicines strictly according to the instructions and only when necessary.
  • Be sure to quarantine newly purchased fish.

The nitrogen cycle can be controlled by tests for ammonia, nitrite, and nitrate. The most important of these is the toxic ammonia test.

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