| | The NITRATE REDUCTOR is a closed system - the water is added slowly so as to achieve the right oxygen levels. The internal pump circulates and mixes the water properly so as to avoid channelling and possible HYDROGEN SULPHIDE production. The bacteria are stimulated using a special biological plastic called DENIBALLS. These provide surface area and food for the ANAEROBIC BACTERIA to keep pace with NITRATE production. The oxygen content is measured with a MV controller to allow the user to accurately control the water flow rate. THE CONTROLLER will maintain the MV reading between -250 and -50 MV ensuring DE-NITRIFICATION happens continuously.
The reactor works as follows. Once the reactor has been filled with water through the probe porthole, the internal pump is activated. Then the controller is set to +500MV. This activates the feeder pump from the aquarium water. After ± 7 days enough bacteria have entered the reactor from the aquarium to begin the anaerobic process. The controller which is probed into the reactor is now set on -250MV. This sets the feeder pump off and internal circulation continues. As the oxygen is depleted the MV reading will fall and anaerobic bacteria will begin to dominate. Small amounts of DEMINAR powder (one spoon) can be injected into the system to speed up the process.
Do not allow air or oxygen to enter the reactor - the outlet pipe must have a one-way valve. As soon as the controller reaches -250MV the feeder pump will activate slowly introducing new water (and nitrate) into the reactor.
This action continues automatically with the MV reading hovering between -250MV and -50MV. Do not overfeed the system otherwise anoxic conditions will develop (MV > -350). Automatic feeding with DENIBALLS is preferred. Proper denitrification conditions will take ± 8 weeks to develop fully. If you have very high nitrate levels (excessive algae! - greater than 10 ppm) and are anxious to reduce it quickly, feed 1 - 2 measures of powder every week until the levels have reduced below 2 ppm nitrate.
The other form of nitrate reductor is where one uses a sulphur-based medium using the same principle as the method already discussed but not requiring food to feed the system such as Deniballs. |