Aqua Medic SN 400 Mode D'emploi page 9

13
Fig. 2: Sulphur-Nitratereductor 400 beside a filter tank or an aquarium
4. Y-piece (not for sulphur version)
5. Adjustion valve for water flow
6. 6/4 mm tube (not for sulphur version)
7. 8/6 mm tube (water outlet to drip counter)
8. T-piece for bypass
9. Pressure line
10.) Filter tank or aquarium
11.) Circulation pump
12./13.) Power plug
2. Theory
In the Aqua Medic Sulphur-Nitratereductor, aquarium water is treated under oxygen conclusion.
With the absence of oxygen, many bacteria are in the position to use nitrate as replacement of
oxygen for breathing.
Oxygen is used for respiration, nitrogen is separated into the water. Nitrogen gas (N2) is
completely harmless as a natural component of air.
Thus, decomposition of nitrate is a pure breath procedure. Additionally, also bacteria need food as
any other organisms. For this reason, the nitrate-reducing bacteria must be fed. The sulphur beads
serve as food which are used at the same time as settlement substrate. Sulphuric acid develops as
a waste product. In order to neutralize this, the Sulphur-Nitratereductor contains calcium
carbonate (Aqua Medic hydrocarbonate, medium). The developing sulphuric acid is converted into
calcium sulfate, which enriches itself in the water in the long run.
When the animals are fed with dried, living or frozen food, proteinaceous substances get into the
aquarium. These are the basics of the diet for the animals. A big part of nitrogen from the food is,
however, excreted into the water. This nitrogen is metabolised by bacteria, living in the aerobic
filter via toxic intermediate substances ammonium and nitrite to the less toxic nitrate. These
biochemical reactions take place in the presence of oxygen:
The bacterium Nitrosomonas oxydizes Ammonia to Nitrite, the bacterium Nitrobacter Nitrite to
Nitrate.
In most aquaria, nitrate is the end-product of bacterial metabolism and accumulates in the water.
Only higher water plants and algaes are able to remove this nitrate from aquarium water.
What is the effect of nitrate in the aquarium?
6
4
5
11
12
CO
2
7
9
8
10
9