The Berlin Method: All You Need to Know About It!

What is the Berlin method?

The basic premise of the method is that live rock is an excellent medium for biological filtration. We all know that nitrifying bacteria cover every available surface of our aquariums, but they are also found in large numbers in filters. This is justified because a considerable amount of water (more food) and oxygenated water flows through the filters. The filters in use today are very efficient in processing nitrogenous waste, when the biological waste is processed in an artificial filter, there is no low-oxygen zone in which denitrification, i.e. the conversion of nitrate to nitrogen gas, takes place.

In a Berlin Method aquarium, the live rock is a natural nitrification filter. There are many nooks and crannies on its surface through which a small amount of water, and therefore oxygen, flows. As a result, ammonia is converted to nitrites and then the bacteria convert the nitrites into nitrates, and in the anoxic areas where denitrification takes place, the bacteria convert the nitrates into nitrogen gas, which then leaves the tank. Just like in the ocean.

How the method came about

The Berlin System, as the name suggests, was invented by a few Berlin aquarists dedicated to their passion. At this point, special mention should be made of Dietrich Stüber and Peter Wilkens, who are among the popular figures in the aquarium community who made the Berlin method widely known. Dietrich Stüber was probably the first hard coral breeder who succeeded in maintaining and even propagating a representative of the genus Acropora. Today, the Berlin System is used worldwide and is one of the most popular systems in marine aquaristics. However, it is used in many variations by marine aquarists all over the world.

What does the Berlin System stand for?

The Berlin System usually consists of the following components:

Live rock (1 kg per 10 l of water), a protein skimmer, strong lighting, macronutrients, activated carbon and a dosing pump and components or calcium reactor.

Live rock

In the Berlin system, the type of rock used is clearly defined. Only live rock is used (dry and ceramic rocks are currently being revived). The advantage of live rock is its porosity;, it contains bacteria and micro-organisms Therefore, denitrification, which is important for nitrate decomposition, takes place inside the live rock.

The more rock, the better, as there will then be more micro-organisms throughout the tank. Of course, certain rules have to be followed when arranging the rock, but this is a topic for another article, which you can find on ReefPedia. The whole process of nitrate degradation can be considered to take place via live rock (or well-prepared dry rock).

Dr Rainer Hirschberger made one more argument that I would like to add.

I think the joke with live rock is that the bacterial populations inside have survived the transport and are multiplying in the aquarium, which contributes to the degradation. Dead reef rock is also porous, but the process of bringing dry rock up to the level of live rock is much longer.


The type of substrate used in the Berlin system is also clearly defined. Most Berliner systems have traditionally featured substrates between 2 cm and 5 cm high, with coral rubble or coral sand predominating. Nowadays, it is very common to find aquaria without sand. See ReefPedia for an article on whether sand is worth using in a marine aquarium.

Trace element supply and water changes

In the Berlin system, trace elements that have been used up are also replenished.

Of course, with the growth of algae and corals in the aquarium, there is no shortage of those willing to consume minerals.

There are quite a few ways to replenish minerals in a marine aquarium.

The simplest and very good way to compensate for minerals that are being consumed, or components that are accumulating in too large quantities in the aquarium, is to do a water change, which can be considered a Berliner. You should change about 10% of the water per week (the amount depends on the aquarium and how it is kept, the stocking, etc.).

The Berlin method was developed some time ago, when other dosing methods were not so popular. Nowadays, a number of options for replenishing fluids are known. The topic of dosing, replenishing fluids or dealing with overruns is well covered in ReefPedia.

About the author

Picture of Damian Krawczuk

Damian Krawczuk

I've had freshwater tanks for a long time, but saltwater aquariums have always fascinated me. At one point I decided that I'd set up a small 50 L cube and I've already been in this hobby for 5 years, spending most of my free time developing my knowledge and skills. Now I managed to combine my hobby with work and I'm super happy.
What I value the most in marine aquaristics is the diversity of species and behavior of animals, even the smallest ones, which can be observed, for example, at night, after a hard day at work. Nothing is as relaxing as staring at a tank teeming with life.