Cycling is generally defined as beginning-or equilibrium of the nitrogen cycle in an aquarium. Fish waste is actually composed of ammonia. This chemical, even at very low concentrations, is very harmful to fish. Exposure to ammonia damages the gills of fish, inhibits the oxygenation of the blood and eventually lead to weakness or death. With many fish in the sea (not to mention other organisms that produce ammonia) at sea, you wonder why help poisoned.Without not with ammonia levels in your aquarium will prove to be a rather complicated and costly. Fortunately you have help. Natural heterotrophic (food waste), the bacteria are present in nearly all aquariums. They are the natural balance of the natural mechanism. They break down ammonia into other toxic chemicals. This process is called the nitrogen cycle and is very important in every niche. Control of this process is generally called cycling.To cycle your aquarium efficiently, helps a lot to learn and the nitrogen cycle, the nitrification process and understand how best to work with it.In typical tank is ammonia released by fish and other invertebrates. This waste serves as food for heterotrophic bacteria Nitrosomonas turnover of ammonia (NH3) a (NO2) nitrite. Nitrite is almost as toxic to fish as ammonia, but this chemical does not last long in an aquarium (except in isolated cases). We owe it to Nitrobacter, other heterotrophic bacteria. It consumes and converts it into nitrite (NO3) nitrate. Nitrate is relatively harmless to fish and other marine animals. The only problem with this is that nitrate fertilizer plants – and algae. However, because of these two beneficial bacteria, fish poisoned.In not most cases, however, ammonia and nitrite levels are still rising cycling.Unfortunately justify the need, Nitrosomonas and Nitrobacter multiplies very slowly at first and , external intervention is sometimes necessary for the levels of nitrite and ammonia in the tank. To help these heterotrophic bacteria, we will see in the process of nitrification process further.The nitrification rate in the best moments is proportional to the heterotrophic bacterial population. This process includes aerobic metabolism and thus oxygen to support it. There are several biological filters heterotrophic bacteria house, but based on experience, Wet / dry filter is most effective. Why is that? Because a filter wet / dry, water tank is exposed to air, which means more oxygen is dissolved in water, it follows that plants that ammonia and nitrite bacteria faster will help. In return, the heterotrophic bacteria fertilize the plants. Now that is balance!