Aquarium chemistry and influencing the water parameters

Aquarium chemistry or aquarium chemistry and influencing the values: Aquaristics is biology and chemistry and many biologists and chemists deal with the connections that take place in this small biotope. We are neither biologists nor chemists, but over the years we have gained some experience to explain some things that go on in the aquarium. Values ​​such as PH, KH, GH or nitrite and Nitrate an important role. Below we explain in simple terms what the individual values ​​are all about and which values ​​are good or bad. There are no chemical derivations based on composition and formula, but this is about the simplicity and the essentials that an aquarist should know at the beginning of his hobby.

 

PH value simply explained

The PH value indicates the acidity of the water. This is usually already specified by the responsible water supplier. There you will find at least information about which PH value is possible in your area.

Aquariums Fish have very different requirements when it comes to the PH value. One thing is already clear. A value below 5.0 PH or above 8.5 PH only most fish will be able to survive in the long run. Therefore, most fish can be kept between 6.0 and 8.0 PH value.

With a value below 7.0 one speaks of sour or soft, if you ever hear these terms in forums and Co. At 7.0 one speaks of a neutral water. Above 7.0 one speaks of hard and basic. You should also be familiar with these values ​​and designations.

The PH value can be verified with the help of a droplet test, which is also available in specialist shops. You should also do this on a regular basis. Fluctuations can also occur quickly here. Especially if you work with automatic CO2 fertilization. Co2 lowers the PH value significantly.

Lower PH value

Let's start first how to lower the PH value. Of course, there are also special chemistry here, which you should not necessarily use. In addition to the possibility already mentioned above, it is possible to use a Co2 fertilization, more options. One of them would be to mix the aquarium water with osmosis water during a water change. This water is very acidic and this would also lower the PH value.

The way food is Filtering over peat is a good way to lower the PH value. Of course, you can also achieve success with a water change without osmosis water, which incidentally requires an osmosis system. At least when acidic water comes out of the tap. Values ​​below 7 also lower the PH value in the aquarium.

Increase PH value

Of course it can also happen that the PH value is too low and this

must increase. However, our experience shows that in most cases it is the other way around. If you still have to increase the value, then there is the possibility of strong ventilation, because this drives Co2 out of the water. Unfortunately, this usually has to do with a reduction in fertilization and thus plant growth.

You can also help with chemistry. Additives like sodium bicarbonate (NaHCO3) help to increase the value. Basically, this is nothing more than baking powder. A water change can also increase the value. Of course, it always depends on the available water.

Incidentally, the PH value can now also be measured electrically with the help of a probe. This is usually done with pre-controlled Co2 systems, and the inlet of the Co2 is thereby regulated.

 

 

KH value simply explained - carbonate hardness

Another value that can be determined with the droplet tests offered is the KH or carbonate hardness. There you can determine how high this value is using a certain drip method. Can usually be read from a color change after a certain number of droplets. The number of droplets then corresponds to the hardness in degrees. Exact instructions on how to use the droplet tests can be found in the detailed operating instructions from the respective manufacturer. The carbonate hardness KH is measured in °dH degrees of German hardness. It forms part of the total hardness, which we will present to you in more detail in the next chapter. This value must also be taken into account. As with the PH value, this value is already specified by the water supplier. In a balanced water, the carbonate hardness is always about 20 percent lower than the total hardness GH. However, it can also happen that the proportion of carbonate is higher than the total hardness.

The KH is closely related to the PH value. It is usually assumed that if the PH value is very stable, the KH is also stable.

Of course, it can also happen that you have to adjust this value because the fish may not tolerate a value that is too high or too low.

 

raise the carb level

The KH value is only rarely increased. It is usually too high and needs to be lowered. If you want to increase it, however, there are corresponding preparations available in specialist shops. Ingredients such as carbonate salts are usually available here. They increase the KH value accordingly.

 

lower the carb level

Lowering the value can happen quite often. In most cases, however, this is also reduced with a too high PH value. Therefore, one can assume that similar things to lowering the PH value also have an effect here. These include, for example, filtering through peat or treating the water with osmosis water and therefore particularly soft water. A weekly water change can help here. Adding alder cones or beech and oak leaves is also good. They also cause a reduction in the KH value. Here you should be very careful with it. The aquarium can quickly tilt accordingly, as other substances from the natural product are also brought into the water.

 

GH simply explained - total hardness

Now we come to the total hardness in the water. Here, too, it is measured in German degrees or °dH for short. It is also measured by droplet tests from the trade. There are a large number of tests here, but they mostly have the same principle. See also our explanation for the KH value and its determination. Alternatively, there are also strip tests. Here a specially prepared paper strip is held in the aquarium water. This is then colored accordingly and you can determine it using a scale. In our opinion, these tests are easy to use but much less accurate. That's why we recommend the drop test. Now let's look at the weights and ratings of the GH value.

 

 

The fish in particular are very sensitive to this value. In general, one can say that all values ​​in the too soft and also in the too hard range are not good. Here, too, one quickly finds out from the profiles of individual fish species that extreme values ​​also occur in nature. In a community aquarium you usually need an average value.

The same applies to increasing and decreasing the total hardness of the water as to the carbonate hardness. The best is Water treatment via osmosis system to reduce the value accordingly.

The guiding principle simply explained

Now we come to the area of ​​electronics, because the conductance is basically the electrical resistance of the water. We do not measure this with droplet tests as before, but here special measuring devices are required. An electronic measurement is now standard in the aquarium to determine this value.

Due to this measuring method, the conductivity is very well suited to constantly carry out a certain measurement in the aquarium water. It ultimately measures the dissolved ions in the water, which in turn are influenced by GH or KH. Giving a benchmark is extremely difficult. Changing the conductance in the tank is good and always requires a certain amount of caution. In the event of a strong and rapid change in the conductivity, one can therefore assume that the total hardness of the water and also the carbonate hardness of the water have changed. We will describe later what can cause this. This is my one indicator of an increase in nitrate. Then the salinity of the water changes and with it the conductance. Fish are extremely sensitive to this, so it makes sense today to think about purchasing a conductance device for measuring.

 

Nitrification of an aquarium simply explained

Let's now come to an exciting topic, because very often there are crucial errors, especially in the area of ​​nitrate and nitrite. Fish deaths can quickly result here. How these values ​​affect each other and what is meant by this has its origin in the nitrification of an aquarium.

The food and the associated excretions of the fish produce ammonium in the aquarium, which in turn is converted to nitrite and nitrate. Influencing factors here are also the plants and the oxygen. Ammonia and nitrate provide food for the plants. In a well-established aquarium, this balance is quite right. Problems can only arise if this is not the case. Usually when either the stocking or the planting does not fit. Balanced planting is not always possible. For example, in a Malawi tank with perch, you will have problems placing enough plants here. Most of these pools are just stone pools.

The stocking is also a decisive factor that can influence this cycle. Above all, the excretions in the form of faeces are decisive. Therefore, you should always feed fish very sparingly and make sure that no leftover food reaches the bottom. At least not if you don't have any bottom-eating fish in the aquarium.

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Ammonium / Ammonia simply explained

In the first step, the excretions of the fish do not produce nitrite or nitrate, as many people wrongly think, but ammonium is produced here. But ammonium and ammonia are not the same thing. They arise in connection with the PH value. Below a PH value of 7 one speaks of ammonium and above a PH value of 7 the proportion of ammonia increases. This proportion is very toxic and often leads to the death of fish in the aquarium. These values ​​are also measured with the help of droplet tests. Usually, however, this measurement takes place very little. Here one usually measures another value in the chain of nitrification.

 

Nitrite NO2 simply explained

Let's now come to one of the most important values ​​and one thing right away. Here you will need droplet tests again and again in the future, so it makes sense to resort to larger tests right away. Strip tests can also be found here in stores.

Basically, nitrate should never be detectable in the aquarium. A value of 0,0 mg/l must be aimed for. Anything above that is harmful to fish and will lead to death very quickly.

Nitrite is mostly caused by the absence of bacteria that break down nitrite. These bacteria are called Nitrobacter. These bacteria are not yet present in a new aquarium. These only develop over time via the filter media.

 

Nitrobacter

If these batteries are not yet present or are insufficient, nitrate will not be broken down and this value will inevitably increase and thus lead to the death of the fish. It is therefore necessary to wait until nitrobacter appear and nitrate is broken down.

 

Nitrite peak and running in an aquarium

At the beginning you will not be able to detect any nitrite in the aquarium water with a droplet test. This is basically logical, because there are no excrements from fish and also no dead parts of plants, which allow the value for the creation through food to arise. Over a few days, however, these waste products become larger and larger and nitrite is also formed. One speaks of a nitrite peak when the nitrite value rises very quickly and then falls again because the nitrobacter degradation bacteria have set in. Only then should you use fish.

That's why you have to measure the nitrite value or content in the aquarium every day right from the start in order to be able to determine exactly when the nitrite peak occurred. Only then is it possible to safely insert the fish.

How long this takes is difficult to say and also depends heavily on the respective pool. With only a few plants, the nitrite peak will be delayed and can last several weeks.

Only when this peak has taken place and a safety period of a few more days has been observed should one think about gradually stocking with fish.

 

 

Can you help to break down nitrite faster?

Yes you can. Basically you have to try to get the bacteria Nitrobacter into the aquarium faster. There are already ready-made bacteria to buy in specialist shops. A second possibility is to inoculate a filter medium with one from an already established aquarium. Here, however, there is a risk of bringing unwanted other things into the aquarium. Algae in particular can then become a problem.

 

What can you do if you have too much nitrite?

Basically, you have to act very quickly. A water change of 90 percent daily, if necessary, must be carried out. What kind of effort this represents, especially in large tanks of several hundred liters, certainly does not need to be mentioned.

Therefore we advise patience.

Once the aquarium has run in and is in its biological balance, there are no more problems and you only have to check the nitrite value from time to time.

 

Nitrate NO3 simply explained

Nitrate is the end product of nitrification and mainly plays a role in plant growth. Plants need nitrate as food to grow properly. Therefore, there should always be a certain level of nitrate in the aquarium. Nitrate and nitrite should not be confused, because the 0.0 mg/L limit basically applies to nitrite. With nitrate, values ​​of up to 50 mg/L are not a problem. However, if this value is higher, it can also be dangerous for the fish.

Nitrate usually only becomes a problem if there is none in the water and the plants are therefore not growing. However, we have never had these problems in practice, because if the nitrification chain is correct, these values ​​are set automatically.

Co2 simply explained - carbon dioxide

After dealing with the waste materials, let's take a look at the CO2 value, which is usually associated with lush plant growth. CO2 is a compound of carbon and oxygen. This is usually determined with a corresponding calculation from the KH and PH value and is therefore closely related to it. Today there are also measuring devices with probes that determine the PH value and then use this value to influence the CO2 value. These are used in automatic Co2 systems.

Maybe a word about calculation. If the CO2 value in the water (dissolved) doubles, the PH value changes by just 0,3 degrees. And although this is reduced. It is assumed that the KH value does not change. The Co2 content in the water is given in mg/l.

This value is extremely important, especially when it comes to plant growth. Values ​​of up to 25 mg/l should be reached. Always in a certain interaction with the PH value.

However, anyone who thinks they can increase the CO2 value even further, so that the plants grow even better, is wrong. This is where more dangers come towards you. Fish have a problem with a Co2 value above 30 mg/l.

 

Attention danger for the fish

Co2 is broken down by the fish through the work of the gills. The body of the fish also creates Co2. If the value is too high, it can no longer be mined and fish kills can begin. Therefore, this value should never be increased above 20 mg/l.

 

How can you increase the CO2 value?

Basically, today you either use self-built Co2 biogas systems or you use a broad portfolio in the trade. There the Co2 is supplied in pressurized gas cylinders accordingly. A simple and very comfortable thing. In addition, the PH value is usually also measured electronically, so that you can also keep an eye on it. How to build a Co2 system yourself can be found in various reports. A good option, especially for smaller tanks.

If you want to reduce your CO2 value in the pool, you can do this very quickly with good ventilation. A diaphragm pump, for example, can do a good job here. By doing this, the Co2 is emitted and the water loses it. You're basically just strengthening the surface movement.

 

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Oxygen O2 simply explained

There is a crucial difference between Co2 and O2, because O2 with oxygen is something completely different from Co2 and carbon dioxide. Oxygen is not only the basis for life for us humans, but also for the fish in the aquarium. As in nature, it is produced by the plants in the aquarium. Especially if you have a strong movement on the water surface you speak of a lot of O2. Examples are strong flowing streams and rivers.

The oxygen content in the water can also be measured using a droplet test. These are usually very cheap. There are also electronic measuring devices to determine the oxygen content, but these are quite expensive.

This value is also measured in mg/L. You should be careful with very low oxygen levels. Critical becomes from a value of 3 mg / L. Above all, when measuring, you should also note that the oxygen value in the water decreases significantly overnight, since production through photosynthesis by the plants can no longer take place. Therefore, the value in the evening must be higher than in the morning.

If you have problems with the oxygen content in the water, then you have to increase the number of plants or you take care of a larger surface movement of the water.

Phosphate PO4 simply explained

This chemical substance is also often used in aquaristics to make certain statements. Mostly related to the keyword Algae or plant growth. Here, phosphate PO4 plays a crucial role because plants use this substance in large quantities. This is also measured using commercially available droplet tests. This value can also be determined in this way.

If it is too high, it can no longer be absorbed by the plants and algae growth quickly occurs.

It is brought in by feeding. Therefore, it is important to feed sparingly here as well. One of the most common mistakes in aquaristics is overfeeding.

If the phosphate value in the tank is not enough, it is usually increased with a fertilizer. However, plants will receive other substances through fertilizer.

If you notice increased algae growth, we recommend measuring this value. If it is too high, then it should either be lowered using special chemicals, or more plants should be provided in the aquarium. Also the water change again play a crucial role in getting excess phosphate out of the aquarium.

 

All about the water change

Silicate Si04 simply explained

Here, too, the water supplier is to blame, because very often silicates and polyphosphates are used by the water suppliers to protect the water from corrosion. Unfortunately, these values ​​can also already be present in tap water in too high concentrations. This value can also be measured with a droplet test. Due to these increased values, there is usually an increased occurrence of pebbles or thread algae. Cyanobacteria are also usually detected more frequently in a tank.

 

remove silicate

Since this is already contained in tap water, as already described above, the question arises as to how it can get out of there again. Basically, there are also various means on the market. Be it the silicate Ex or other substances that ensure that the silicate is at least reduced. Unfortunately, there are only a few ways to reduce the silicate. A minor filtering of the water often helps to get rid of the algae.

Many aquarists also swear by the mixture of tap water rainwater, in order to reduce the silicate content. One always reads about an osmosis system, which treats the water accordingly. Unfortunately, this will not bring anything, because the silicate is not removed by the osmosis.

 

Iron Fe in the aquarium simply explained

Iron is also a substance that can be measured and determined in the aquarium. This is influenced by the fertilization of the plants. Therefore, you should measure the iron value, especially if you have problems with the growth of the plants. This is also measured by droplet tests. The unit for this is mg/l. If you have too much iron in the water, which in our experience should almost never happen, unless you accidentally put too much fertilizer in the tank, then you should do a big water change.

 

Copper Cu in aquarium water

Unfortunately, it happens again and again that copper gets into the aquarium water. This should not be the case, because copper is extremely harmful, especially for the fish. Nevertheless, it can happen, especially in old water pipes, that copper dissolves and thus gets into the water, for example when filling or changing the water. We therefore recommend testing your tap water for copper. This is also possible with the droplet tests. Copper lines were used very often in the past. Today, these have mostly been replaced by plastic lines. Nevertheless, the copper can be dissolved, especially when using warm water.

You could also get copper problems from the use of medication. Usually the copper values ​​are also increased in this context. That's why it's important to know exactly what you're doing when it comes to fish diseases. Especially if it only affects one species or race.

 

sulfur S, zinc Zn and potassium K

Of course, there are a number of other substances that can occur in the aquarium. We will not explicitly present these here, because they only come into their own to a limited extent in the aquarium and usually do not cause any problems. However, if you have them in larger quantities, you are welcome to contact us.

 

Interaction of the individual substances and compounds

Finally, a few words about the interaction of the individual additives, values ​​and chemicals that can be found in an aquarium. If you have read this article in peace, you ask yourself what can happen to you. We would like to take away some of the fear here, because most of the time the values ​​set themselves and there is a balance. Nevertheless, certain irregularities can occur in the aquarium and then the search begins.

In forums or Facebook groups you will be asked again and again to name your water values ​​and then you should know them or be able to check them. Appropriate advice and help is then usually available to solve the problem.

Nevertheless, a lot seems to vanish into thin air if you don't neglect and conscientiously carry out the initial running-in of an aquarium and the subsequent care.