Humic substances are degradation products of dead biomass. They are part of humus, which is all of the organic, decomposing matter in the soil. As part of this soil, humic substances represent various complex macromolecules. In the wild, humic substances play a very important role in making hostile conditions usable for aquatic creatures. Only by using the humic substances are the living creatures in such waters able to accumulate enough vital minerals, such as calcium for building bones. Therefore, humic substances are even essential for the survival of animals that come from such black water habitats in the aquarium, as they have adapted very strongly to the presence and use.

Tannins in water are a cause of brown or yellow water. The best known tannins are tannins and flavonoids. In the aquarium they make the water more acidic and thereby inhibit, among other things, pathogens. Tannic acids are natural ingredients from various plants such as alder, oak, beech, sea almond trees, cinnamon and so on. These are aromatic compounds that contain phenol groups. Just like humic substances, they make the water more germ-free thanks to their antibacterial and fungicidal effects. They also give the water an amber tone and ensure a corresponding osmotic value. However, in addition to the slightly coloring and acidifying effect, humic substances have many other positive properties that tannins lack. So it may not be enough to add a few alder cones to the aquarium.

A biotope is a spatially limited habitat of certain plants, animals and organisms. The biotope is characterized by a wide variety of environmental factors. These include, for example, wind, heat, light, the subsoil or the water supply. They shape the respective location and create the conditions for the life of different plants and animal species. Some species can be found in several biotopes. However, some species are also endemic. This means that you can only find them in this one biotope.