In the cupboard underneath the aquarium with the technical equipment, the engine room, so to say, the same neatness rules. On the right on the foreground a Co2 diffuser, marke EIGENBAU, the hallmark of the aquariumvrienden at Zwolle. Work of a well organized technical board under the supervision of president and member of the committee of the N.B.A.T.. There is also to be seen a piece of the biological filter with a compartment with ceramic substrate with in a compartment beside it a copmpartment with the pump and the heater. In that way he Will never be seen.