| In short : Installing its very first aquarium is an exciting adventure, but the aquatic environment is a fragile ecosystem that does not forgive improvisation. To avoid disappointment and preserve the life of your future residents, here are the 5 critical errors to avoid at start-up: – Error 1: Introduce fish on the first day. This is the most common and deadly error. An aquarium needs 3 to 4 weeks of empty operation for the “Cycle of the Zote” to be set up. – Error 2: Choose an aquarium that is too small. Contrary to popular belief, a small volume (like the red fish bowl) is much more difficult to balance and quickly becomes toxic to fish. – Error 3: Wash the filter and the decor with running water. The chlorine present in tap water instantly destroys the good bacteria essential to the survival of the ecosystem. – Error 4: Overfeeding. Distributing too much food pollutes the water in a dazzling way, causing spikes of deadly nitrites for the fish gills. – Error 5: Overcrowding and poor cohabitation. Wanting to put too many fish or mixing species with incompatible needs (hot and cold water) inevitably leads to stress and disease. |
Create a magnificent aquatic landscape at home, admire the colorful ballet of fish… Laquariophilia is a fascinating hobby. However, for many beginners, the experiment is cut short: in a few days, the water becomes cloudy, the fish adopt an abnormal behavior, pipe air on the surface, and end up dying one after the other.
This phenomenon, often called “the new baccalaureate syndrome”, is not a fatality or a lack of luck. This is almost always the direct consequence of major technical errors made during the first few weeks. To begin with serenely, here is the guide to the 5 death traps to be absolutely circumvented.
The 5 fatal errors of the beginner
1. Failing to respect the lazote cycle (the nitrite peak)
This is the number one cause of mortality in aquariums. The fish produce waste (excavation, food scraps) that turn into ammonia, then into nitrites (NO2), a violent poison that blocks the breathing of fish.
To eliminate this poison, Laquarium needs to develop colonies of “good bacteria” capable of transforming nitrites into nitrates (NO3), much less toxic. This biological process takes time.
- The absolute rule: you have to run a quarium filled, planted and filtered, but Without any fish, for a period of 3 to 4 weeks. This is the time necessary for the nitrite peak to take place and disappear.
2. Start with too small water volume
The mythical round jar for goldfish is an organic heresy. The more a volume of water is restricted, the more the chemical parameters (pH, hardness, temperature) swing suddenly at the slightest change. The slightest pollution takes on dramatic proportions.
- The advice to start: An aquarium of 60 to 100 liters is ideal to start. It offers excellent biological inertia, which means that small dosage or maintenance errors will naturally be buffered by the medium, leaving time to react.
3. Clean the filtering masses with tap water
The filter of your aquarium is not just an impurity strainer: it is the biological heart of your tank, the place where the majority of useful bacteria reside. Tap water contains chlorine and chloramines, disinfectants designed to kill bacteria.
- The right method: Never clean the filter foams under the tap. Rinse them only very superficially in a bucket containing Water taken directly from the Quarium during your weekly water change.
4. Give too much food
The beginner’s natural reflex is Generously feed your fish for fear that they will starve. It’s a dangerous calculation. The stomach of a fish is tiny. Everything that is not consumed in less than two minutes falls to the bottom, saturates the soil, rots and causes unwanted massive organic pollution.
- The right dose: Distribute very small pinches once or twice a day. All flakes or pellets should disappear in less than 90 seconds. Introducing one fasting day per week is also excellent for the fish digestive system and water cleanliness.
5. Overcrowd the bin and mix the species
Each fish needs a minimum living space to swim and limit their stress. Moreover, we cannot associate any species. A goldfish (cold water, 15-20°C) cannot live with a guppy or neon (tropical water, 24-26°C). Similarly, mixing territorial or aggressive fish with calm species generates deadly chronic stress.
- The good reflex: Find out carefully about the breeding sheets for each species before purchase (default settings, minimum volume required, social behavior).
Summary table: Errors, impacts and solutions
| Mistake made | Consequence for fish | Technical solution |
| Immediate fish addition | Acute nitrite poisoning (asphyxiation). | Wait 3 to 4 weeks vacuum break-in. |
| Volume less than 30L | fatal thermal and chemical variations. | Start with an aquarium 60L minimum. |
| Cleaning the filter under the tap | destruction of useful bacterial flora. | Rinse the mousse in Laquarium water. |
| Chronic overfeeding | Oxygen drop, water pollution peak. | feed in 90 seconds maximum, once a day. |
| Random mix of species | Stress, aggression, environmental diseases. | respect the Parameter Compatibility water. |
How to react in an emergency when starting up?
If you read this article while your fish have already been in the quarium for two days and they swim on the surface by pipe as much, you are in the middle of a peak of nitrites.
To try to save them:
- Immediately change 50% water of laquarium with water at the same temperature, previously treated with a water conditioner (which neutralizes chlorine and heavy metals).
- Stop the power completely For 3 to 4 days (a fish can fast without any problem, but the food aggravates the pollution peak).
- Add live nitrifying bacteria Trade directly in water and in the filter to artificially accelerate the creation of the biological cycle.
- Test the water daily Using drop tests (more accurate than strips) to monitor NO2 levels.
FAQ: Your Frequently Asked Questions
How do you know if the lazote cycle is over?
The only reliable method is to test your water using “drop” (NO2) type chemical tests. Around the 10th or 15th day, you will see the rate of nitrites soaring (peak). Then, this rate will gradually descend until it reaches a level strictly equal to 0 mg/l. Once the nitrites are invisible for 3 consecutive days, the tank is ready to welcome its first fish.
Why did my water turn white/disorder after 3 days?
It is a very classic phenomenon called “bacterial explosion” or bacterial bloom. Millions of microscopic bacteria grow in suspension in water to colonize this new environment. Above all, do not change the water or panic: this is a normal start-up step. The water will clear up on its own in 48 to 72 hours.
Can chemicals be used to avoid waiting 4 weeks?
Some commercial products called “Bacteria Starters” promise the introduction of fish in 24 or 48 hours. If they actually contain useful bacterial strains, experience shows that it is much safer to let nature take its course. Using these products makes it possible to secure the start, but does not exempt from waiting at least ten days for safety to let the ecosystem stabilize.