The 10.000 litres tematic aquarium of Masoala at the Zoo Zurich

Filtration system

The filtration system, like we said before, is relatively simple and based on the classical Berlin Method. The two main components are an enormous protein skimmer Royal Exclusiv Bubble King 2500 and a big macroalgae filter with opposite photoperiod compared to the main tank, in order to keep the pH high in the night, a period when the pH normally drops down. In addiction every month a small amount of activated carbon is used for the duration of 4/5 days. To help the filtration 30% of the rocks in the tank are live rocks and there are 4-7 centimeters of live sand.

il filtro a macroalghe

The macroalgae filter

L'enorme schiumatoio Royal Exclusiv Bubble King 2500

The oversized skimmer Royal Exclusiv Bubble King 2500


Some integrations are made every day to let corals grow. More precisely four different products from the brand GroTec are distributed through dosing pumps: Coral A, Coral B, Coral C (in order to integrate trace elements) and VitAmino for vitamins and amino acids.

Calcium and magnesium are supplied by calcium reactor, an economical solution for such a big aquarium.

Il locale tecnico

The technical room


Every day the protein skimmer is manually cleaned as well as glasses, furthermore a visual inspection of every function is performed. Every two weeks there is a change of 10% of the water. The big amount of biomass contained in the tank helps the growth of many small algae like diatoms that are covering the glasses in a few hours and have touched the quality of our photographs.

For the extraordinary maintenance there is the possibility to rise the illumination system (that is hanging just a few centimeters over the water) and do snorkeling in the tank. For more complex operation it is also possible to use a full scuba diving equipment.

Un acquario per la quarantena degli animali

A smaller tank used to quarantine animals

The water quality is normally measured by colorimetric tests (Red Sea and Salifert). Nitrates are about 5mg/l (this is the target value) and phosphate are less than 0.1mg/l (critical value), normally they are at around 0.05mg/l. Other chemical values are kept as we expected: Calcium 400mg/l, magnesium 1120mg/l and dKh at 8. The doctor Martin Bauert has explained to us that they tried to change nitrates’ and phosphate’s concentrations but this had brought many problems, like bleaching of the corals happened in the past, problems to soft corals or reduced growth. Therefore, they choose to maintain such a values and we find parameters we could perceived as relatively high in our domestic aquariums.

Acanthurus sohal al Madagascar Reef Aquarium dello Zoo di Zurigo

Acanthurus sohal at the Madagascar Reef Aquarium of Zoo Zurich

The water temperature is kept constant at 24°C with a complex cooling systems which has also full backup.

Il locale tecnico visto dall'alto, si noti a sinistra il recipiente per i cambi d'acqua

Technical room from above. The big tank is used fot the water changes.

Behind the scene

As you can see from the pictures, behind the main tank there is the presence of a big technical room that enables to work easily on such a big system. This is quite a dream for us reef keepers… There is a gangway at the same height of the water in the aquarium, a big tank for water changes, instruments for controlling water level and external return pumps which also contribute to water movement.

There are also many Tunze controller, the calcium reactor and some jerry can for the integrations.

We could also see a smaller aquarium used for quarantine and to teach to new reef keepers, containing fishes and corals.

I controller Tunze

Tunze controllers


There are so many animals in such a tank that it is difficult to monitor all of them. We got a long list, in this chapter, we tried to complete it with some photo, where possible.