Berlin system
The Berlin system enables hard corals, Caulastera furcata, to be kept in the Berlin Zoo aquarium
The Berlin system describes a method with which reef aquariums are operated. In contrast to the previously usual pure fish aquariums decorated with dead coral sticks, which contain no or only a few invertebrates , the Berlin system enables hard corals to be kept in an aquarium . It was developed by the aquarist Peter Wilkens and a group of seawater aquarists from Berlin.
The following components belong to the Berlin system:
- An aquarium with a surface drain and a lower tank . Many harmful substances collect on the surface of the water. The water falls through a pipe that extends to the surface of the water into a second, smaller tank in the aquarium cabinet, passes through various chambers in which there are other technical devices such as skimmers and calcium reactors, and is finally pumped back into the aquarium by a feed pump .
- The most important device in the lower tank is the protein skimmer . It is used to remove toxic protein compounds. With the correct setting, around 80 to 95 percent of all proteins are removed from the water before they are biodegraded.
- Living stones : These are natural, porous limestone from coral reefs, which is broken out and sent wet (by plane). Living stones were made up of hard corals and still contain a wide variety of living things such as calcareous algae , worms , tiny snails and crustaceans . Above all, the bacteria are important. In the outer areas of the stones, in which oxygen is still present due to the slowly diffusing aquarium water, ammonia , ammonium and nitrite are broken down ( nitrification ). Nitrate is broken down ( denitrification )in the interior of the stones, where there is a lack of oxygen. The living stones serve as a biological filter. Since they are very expensive, only one third of the aquarium is now set up with living stones, the rest is decorated with other porous limestone. If it is sufficiently porous, it will also be colonized by bacteria over time and will then function as a living stone.
- An occasional filtering through activated carbon. It removes phenols and yellow substances that are produced by the metabolism of bacteria.
- Strong lighting with metal halide lamps (HQI), optionally combined with blue fluorescent tubes ( T5 or T8 lights , whereby T8 is actually already outdated), or pure lighting with modern T5 lights.
- A strong water movement, for which additional flow pumps are used in addition to the feed pump of the lower basin. The aquarium water should be completely circulated at least ten times an hour. The current is necessary so that the water diffuses through the living stones and so that the metabolic products of the sessile corals are transported away.
- Calcium addition through lime water or a calcium reactor . Corals and other animals with calcareous skeletons use up the calcium dissolved in the water. It must therefore be supplied again later. A calcium content of around 420 mg / l should be aimed for.
- Trace elements such as strontium , magnesium and iodine are also added.
Little soil is used in the Berlin system.
It is the most widely used system for keeping tropical marine animals today. There is also the Jaubert system , the sludge filter system and the Deep Sand Bed .
literature
- Fosså, SA & Nilsen, AJ (1992): Coral Reef Aquarium, Volume 1 . Birgit Schmettkamp Verlag, Bornheim.