top of page
parametres ideaux

Explanation of the parameters

Comment augmenter ou baisser la dureté de votre eau en bas de page.


Organic waste is transformed into ammonia (NH3) which is very dangerous for fish and ammonium (NH4) which is not very toxic. Ammonia is transformed into nitrites (NO2-) thanks to a nitrifying bacteria called Nitrosomonas . It is important to regularly check the concentration of nitrites, because even in low concentrations, it affects the red blood cells of aquatic animals, reducing their capacity to carry oxygen and thus causing suffocation and death of the fish or axolotl. Ideally, the nitrite level in the aquarium is zero.

The nitrites are then degraded into nitrates (NO3-) by the action of the Nitrobacter bacterium. Nitrates can turn back into nitrites [if your changes in au are not made regularly to lower nitrates (No3)], nitric oxide, nitrogen oxide and then nitrogen gas (N2). This information tells us that we must actively monitor the presence of nitrites (NO2-) in the aquarium otherwise all life in it will die quickly . It is also important not to overfeed the fish and to regularly clean the bottom of the aquarium: this eliminates the main source of organic waste. The nitrogen cycle also teaches us that it is important to change part of the water regularly because if bacteria make it possible to recycle organic waste, the non-renewed water in an aquarium inevitably sees its nitrate level rise. . In addition, the bacteria we discussed above are not naturally present in water, so there must be an external supply of these bacteria.

Urgency to lower nitrites, but only if there is no other solution because it is always better to avoid any addition in the aquarium, and let nature work. Nitrit-minus


The main causes of too high nitrate levels

The nitrate level must remain below 20 mg / liter. Beyond that, it becomes dangerous for axolotls and fish. If the nitrate level exceeds 25 mg, here are some possible causes:

- Excess of food

- Overpopulation of the tank (never exceed 1 cm of fish per liter, this is only valid for small fish. A large fish such as the discus or the scalar needs 50 liter on its own

) - Poor maintenance of the tank: water changes not frequent enough, leaves of dead plants left in the tank, filter too dirty or in poor condition ...

- Water changes with water loaded with nitrates (rare). Plants play a role in regulating nitrate levels, since they consume them to grow. It is therefore important to plant well, when the tank and the housed population allow it. If your pipe water is loaded with nitrates, resins are sold to lower this rate, they should be incorporated into the filter media. The totally natural ones have been listed for you here .

In addition to this, you will need to know more about it.

Here are the main water parameters to know in aquariums. There are still many others such as Po4 phosphates (toxic), iron (necessary for plants). The important thing is to respect the needs of the fish, to maintain the tank regularly and not to play petty chemists: no need to buy so-called “miracle” products which are supposed to modify the parameters (pH, nitrates.). They can be dangerous and completely disrupt the balance. Regular tests verify the quality of the water. In strips or drops, there are all kinds. Drop tests, although more expensive, are the most accurate. (see below)

Water quality in France new UFC QUE CHOISIR card:


Green : Low Hardness, GH <9
Orange : Medium Hardness, GH> 9 <15
Yellow : Strong Hardness, GH> 15 <20
Blue : Very High Hardness, GH> 20

In addition to this, you will need to know more about it.

Ideal values for our axolotls


In short !


GH in detail

The total hardness, GH (or TH in French degree but never used TH = 1.78 × 1 ° GH): it corresponds to the calcium and magnesium salts contained in the water and results from the accumulation of the carbonate hardness and the permanent hardness. The richer the water is in calcium and magnesium salts, the harder and therefore calcareous (commonly) it is.

A GH hardness of 5 ° to 10 ° corresponds to soft water. Some tests are displayed in German degrees, the tests giving this value. To convert TH into GH, multiply the TH value by 0.56 Carbonate hardness (KH in German degree or TAC in French degree): these are the carbonates and bicarbonates of calcium and magnesium which disappear after boiling water . They are therefore temporary. KH acts as a buffer on the pH. Permanent hardness: these are the calcium sulphates and chlorides which remain present after boiling. The pH: it corresponds to the degree of acidity of the water. Below 7 the pH is acidic, above 7 it is basic, equal to 7, it is neutral. The pH varies during the day: at night it decreases because the plants reject CO2, during the day it rises because the plants consume the CO2 for photosynthesis. The most important parameter to take into account for the welfare of the fish is the total hardness. It is necessary to respect the requirements of the fish with regard to this parameter. The pH must also be respected, especially for very delicate species such as the Discus for example. Axolotls need hard water that is either hard (GH = 10 to 15) and basic (pH> 7). Below 10 for the GH we are in soft water, that is to say going towards acidity. However, the minerality of water is essential for the proper functioning of the axolotl organism and especially of its digestive system. Above 20 we are on a very dangerous GH on the other hand, be vigilant. Recurrent yeast infection is often caused by inappropriate or abruptly changed GH.

Augmenter la dureté de l'eau

Il suffit d'utiliser  les minéraux PREIS pour discus qui procurent tous les minéraux et les oligo-éléments nécessaires à l´eau osmosée et à l´eau de conduite lorsqu'elle est trop douce, afin de rétablir l´équilibre. Grâce aux minéraux PREIS pour discus, vous rétablirez rapidement et de manière professionelle une carence en minéraux.

Diminuer la dureté de l'eau

Vous devez utiliser de l'eau déminéralisée, en vente en magasin d'aquariophilie ou bien en achetant votre osmoseur en voici quelques uns : AQPET OSMOSY3 ou bien Geekpure Système et Measury Osmoseur

L'évaporation naturelle de l'eau d'un aquarium, fait que l'eau restante est de moins en moins dure, minéralité qu'il faut corriger par des remplacements partiels d'eau.

bottom of page