The cycling of the aquarium is necessary to turn a bucket full of water into a habitable place for our fish.
I hope that if you are reading this article, it is because you are going to start setting up your aquarium for the first time and you do not want what promises to be a precious hobby, turn into a real disaster.
When we start to set up our aquarium for the first time, it does not have the right conditions to host life. At the moment it is not functional, but we will achieve it through cycling.
What is aquarium cycling?
Cycling is a process by which we get colonies of bacteria to begin to settle in the aquarium, to help us with the nitrogen cycle .
The bacteria that settle in the aquarium are part of the water filtering system. Thanks to its beneficial effects, part of the aquarium’s own waste is degraded in a totally natural way, maintaining the natural balance of the ecosystem.
What happens if I don’t cycle the aquarium?
If you do not cycle the aquarium and just buy your new aquarium you introduce fish, most likely they will end up intoxicated and die.
In the best of cases, they can suffer all kinds of diseases and especially stress, due to being in an environment without enough quality to survive.
How to start cycling?
The first thing we have to do to start cycling the aquarium is to start it.
First of all, we will have to have decided what type of aquarium we would like to have, to then introduce the elements that will be part: substrate , decoration … everything except the fish, and in the first phase we will not introduce plants either.
Of course, the aquarium filter should not be missing, which is very important for the cycling process to be correct and for the first bacteria to appear.
You have to connect everything you need to reproduce the chosen biotope: heaters and lights, although we will not put them on until we put in the first plants.
How long does the aquarium cycle take to complete?
The time it takes for the cycling process to complete varies depending on the type of aquarium.
For a freshwater aquarium, one month is likely to be enough, while in a marine aquarium it takes between two and three months to stabilize all the parameters.
How do you know if the cycling process has finished?
In the first two or three days after introducing the water into the aquarium, we will observe that the water is cloudy due to the effect of filtering and due to the various suspended matters that come from the substrate.
Later, the water begins to clear until it is completely transparent . We can think that the process is over and that we can start introducing fish… No !!
Throughout the process we must periodically control the quality of the water, using the different tests available for this purpose.
Once we manage to eliminate the ammonia and the nitrites drop to zero levels, we can say that the process is over and we can start introducing fish.
The cycling process step by step
The process for cycling the aquarium can be divided into three distinct phases:
1st Phase, appearance of nitrifying bacteria
In the first phase of cycling, the nitrifying aerobic bacteria Nitrosomonas appear, which are responsible for consuming ammonia and converting it into nitrite.
In order for Nitrosome bacteria to make an appearance and thrive, we need the aquarium to contain Ammonia. We can get the aquarium to generate ammonia in three different ways:
Adding fish food
The fish food produces ammonia to the decay . You have to add three to four scales per day, for every one hundred liters of aquarium.
We will achieve the best results by crushing the scales, so that the decomposition is faster.
We will continue with the process, until we manage to raise the level of nitrites present in the aquarium.
Logically this process has its advantages and disadvantages , such as that the process is somewhat longer than if we use chemical products or that we have less control.
However, not everything is bad, the great advantage is that we do not add chemicals to the aquarium, their use is always debatable and we provide useful phosphates for the aquarium plants.
As what we need is for the ammonia to appear so that nitrification begins, we can add it directly, as long as it is pure, without perfumes or detergents.
If we opt for this solution, nitrification will start much faster, but it requires great control over the process.
You have to add 5 milliliters a day, for every 100 liters of water constantly, during the first 10 days. We must control by means of an ammonia test that the concentration does not exceed 7 mg / l, we must obtain results and a good colony of bacteria with a concentration between 2 and 5 mg / l.
After the first seven days, the nitrite level should start to grow. We must control its evolution by making the necessary controls to the water and when it reaches the level of 0.5 mg / l, we must stop adding ammonia.
Test and Kits to measure water quality
In the market we will find all kinds of aquarium water quality tests and meters .
Some are specific, to measure the alkalinity of the water (pH), the calcareous hardness (KH), its hardness (dH), levels of nitrites (NO2), nitrates (NO3) and ammonia (NH3).
In addition to the tests aimed at measuring each of the parameters, there are another series of Analysis Kits that serve to measure all the parameters.
Its effectiveness varies from one model to another, the strip ones being the simplest, but least reliable.
Add resistant fish little by little
It is not the most logical and desirable option, if you are a true animal lover.
By introducing some fish capable of resisting high levels of ammonia and nitrites, we will get the bacteria we need to appear quickly, but at the high cost of the stress that we are going to put on the animals.
A completely unnecessary stress, as a functional aquarium can be achieved with patience.
Tips for the first phase of cycling:
- Plug in the water heaters and maintain a constant temperature of 25ºC. The appearance of the first bacteria is favored.
- Don’t turn on the aquarium light. We avoid the appearance of algae.
- The filter must be running, so that there is good oxygenation of the water. The bacteria in charge of nitrification are aerobic, they need oxygen.
It is recommended to use a porous material, where bacteria nest more easily.
- In this first phase avoid introducing plants, which are clearly ammonia consumers and will prolong the cycling time.
2nd phase of cycling
In this second phase of cycling, Nitrobacter bacteria appear, which are the ones in charge of eliminating nitrites and converting them into nitrates, fertilizer for plants to grow healthy and closing the nitrogen cycle.
- We can see how the nitrite level rises, while the ammonia level is placed at a minimum.
- In this phase we will introduce the aquarium plants .
- You have to connect the aquarium lights between 5 and 6 hours a day, so that the plants can feed and complete their biological cycle.
It is not advisable to go beyond those 5 or 6 hours of light, to avoid the appearance of algae.
- We must suspend the use of ammonia or fish food , when reaching the nitrite level of 0.5 mg / l.
The second phase will be over when the nitrate level drops to zero. We can see how nitrites increase progressively, to stabilize and finally go down to zero.
3rd Phase. Nitrates
Once phases one and two have concluded, what remains is finally to check that nitrates do not exceed the level of between 5 and 10 mg / l.
It is advisable to carry out partial water changes, when the level reaches 25 mg / l, and it is necessary to avoid reaching dangerous levels, such as 40 mg / l.
Introducing fish to the aquarium
Once the cycling process is complete, we can start introducing fish.
You have to be careful to measure and control the different parameters of the water: pH, KH and GH.
Each species needs certain parameters to live. If you are going to introduce several different species of fish, you have to take into account different aspects, such as compatibility between species, if they share different needs for temperature or pH.
The characteristics of the water can be modified, although it usually takes some time and sometimes more money is spent.