Having a good filter is ideal ornamental fish hobbyists. A good filter will promise a good performance so hopefully aquarium water quality issues can be dealt with perfectly. Aquarium filters are commonly known so far, in particular the biological filter, more made up for an aerobic environment for ease of application. The end result of this type of filter is nitrate.
Although nitrates are far less dangerous than ammonia or nitrite, its presence is still have to watch out. To a certain extent nitrate levels remain would create disruption in fish that are kept in a closed system like an aquarium. Therefore, on an ordinary type of biological filtration, water replacement, although with a very long period, it still remains necessary to dispose of nitrate accumulated in the aquarium water.
In contrast to changing the form of ammonia to nitrite and then to nitrate, conversion of nitrate to nitrogen requires an anaerobic atmosphere, an atmosphere without oxygen. In this process involved bacteria decomposing nitrate-bekteri live anaerobically. They get oxygen to consume the oxygen contained in nitrate (NO3).
Creating an anaerobic atmosphere so that the anaerobic bacteria would grow in an aquarium is not an easy thing. In an aquarium oxygen-rich conditions was desired that farmed fish is always a supply of oxygen sufficient for his purposes. Therefore, under normal aquarium conditions, an anaerobic condition is relatively difficult to make. To create an anaerobic atmosphere needed special tricks, one of which is by using a coil system.
Figure 13. Filter Koil Denitrator
The picture above shows a simple schematic denitrator a coil, or a coil decomposing nitrate. A coil denitrator is a coiled hose or pipe which is stored in an enclosed space. No part of the space that relate directly to the open air. This is a key requirement of a coil denitrator, namely an anaerobic atmosphere. The rolls pipe contained in the airtight chamber is a major player in reducing the oxygen that comes from a very rich aquarium oxygen.
Oxygen-rich water that is supplied through a pipe from the main aquarium will be forced to flow in the pipe coils. At the ripe filter condition, the inner wall of this pipe will already be overgrown and inhabited by bacteria decomposing ammonia and nitrite. As mentioned earlier, both aerobic bacteria. Therefore, when water flows inside the pipe, the oxygen contained in the flowing water is consumed by bacteria earlier. Thus when the water leaves the pipe end C, the water no longer contains oxygen.
As a result, the indoor water becomes anaerobic alias D does not contain oxygen. In this condition, anaerobic bacteria will be able to grow freely. They will grow on media that has been provided in the space. The medium can be either gravel or too bioball, as well as the media used for bacteria decomposing ammonia and nitrite. Selanjutkan these bacteria will consume the nitrate that had been produced by a type of bacteria before, into nitrogen.
Then they are removed through a pipe B. The water coming out of the pipe and an oxygen-free water. Therefore, before being returned to the main aquarium, it is recommended that aerated water beforehand. In principle, in a coil denitrator, the longer the hose reels are used, the better because it will provide more opportunities to the water flowing to the oxygen consumed by aerobic bacteria that grow in the pipeline.
Water flow should be arranged in such isedemikian, so it is not too fast or too slow. If the water flow is too fast, then it most likely will not be exhausted consumed so that an atmosphere without oxygen will not be created. If this happens then the nitrate decomposition process will not occur. Whereas when it is too slow, it was likely to be tercipat H₂S highly malodorous and can disrupt the lives of fish in the main aquarium.
Therefore, the water flow should be routed along with the measurement as a benchmark to determine the appropriate water flow.