9
(the filter starts to smell badly). On the other side, zones with a rather high flow may arise where nitrate is
reduced only to nitrite. In each case, the conditions vary in the different zones of the filter and it is nearly
impossible to find its right working point.
These unpleasant effects are avoided by the construction of the Aqua
Medic Nitratereductor.
The recirculation
ensures a complete mixing and the same redox potential level in the whole filter. Zones with a very low redox
potential and the production of hydrogen sulfide are avoided.
The redox potential can be used for the control of the filter. The effectivity and the reliability of the filter can be
increased.
5.
Connections
The following connections are located at the Nitratereductor:
- Inflow
(needle valve [1]): Here, you can connect a 6 mm air tube. At the inflow, you find an adjustion valve
to adjust the flow rate. The best value is approx. 10 - 30 l/h. The adjustion at the inflow causes a delay until
you can read the adjusted drop number at the drop counter at the water outlet. The drop counter is mounted
inside of the aquarium, close to the water level. If the flow rate is regulated in the outlet, the valve may not
be closed completely in order to allow produced nitrogen to escape. During the start phase in the first weeks,
the outlet valve should stay completely open. The inlet has an internal elongation that prevents that gas
enters the inlet tube.
- Feeding (3):
Through this opening, you can inject denimar-Powder with a syringe to enhance denitrification.
Dissolve the powder beforehand in some water. The valve has to be cleaned and closed after every feeding.
-
Redox electrode:
Through this opening, you can put the pressure resistant ORP electrode with standard
thread (PG 13.5) (not included in shipment). Aqua Medic No.: 220.18.
-
Outflow:
Here, you can connect an air tube 6/4 mm, preferably, a black one to prevent algae growth.
6.
Set-Up
The Nitratereductor is a hermetically closed system. The produced gas (nitrogen and CO
2
) can escape through
the water outlet. For this reason, the outlet should never be completely closed because an eventual overpressure
may escape through the water inlet and interrupt the inflow.
The Nitratereductor
has to be placed in a way that the water can flow off either directly back into the aquarium
or into the filtration chamber. In a saltwater aquarium, it is advantageous if the outflowing water is flowing into
the inlet of the protein skimmer or the trickling filter. In the protein skimmer, the water is saturated with oxygen
before it comes back into the aquarium.
- Inflow:
The inflow into the reductor can be realized as a bypass from the main circulation pump with the
included T-pieces. The flow rate is adjusted with the valve and the drop counter.
7.
Starting
Before starting, the
Nitratereductor
is filled with aquarium water and controlled for leaking and the right
position of the sealing. Take care for exact positioning of the O-ring. The circulation pump can be switched on
already.
Connection to an existing aquarium
If a Nitratereductor is connected to an existing aquarium with a rather high nitrate level, the inflow of aquarium
water should not immediately be started. The bacterial growth is enhanced by the addition of 4 dosing spoons
denimar-Powder
.
If, after 8 - 10 days, the nitrite has disappeared from the reductor - a residual concentration
of nitrate is harmless - the water flow can be switched on.
Connection to a new aquarium
If connected to a new aquarium, the bacteria do not have to be fed within the first 4 weeks as the nitrate forming
bacteria Nitrosomonas and Nitrobacter need this time to develope and to oxydize the whole amount of ammonia
and nitrite into nitrate.
