How does the nitrogen cycle start in an aquarium?
1 Answer
While the nitrogen cycle in an aquarium can start with fish, the cycle is often a product of human intervention.
Explanation:
The nitrogen cycle in an aquarium is usually aided by a little human intervention.
Ammonia or NH4+ is present in the waste of fish, thus placing fish in the aquarium will eventually lead to them excreting waste and nitrogen entering the aquarium. Starting the cycle this way can potentially be dangerous and even deadly for most fish. Fish cannot tolerate high levels of nitrogen, and it takes time for nitrosomonas and nitrospira, types of bacteria that transform the ammonia so that it can be used by plants, to develop and reach substantial population levels.
Because of this, humans usually help the aquarium along in a number of ways. It takes week for the bacteria to grow, so having an aquarium with no fish but adding pure ammonia to it regularly is one method of starting the nitrogen cycle. Add in a little patience, testing kits, and eventually the aquarium is safe enough for fish. The cycle continues naturally once the fish are added.
Another method is to use fish food to start the cycle. This is a source of ammonia and, again, over time the cycle will develop as the bacteria grow. Eventually, fish can safely be added to the tank.
Lastly, some people will simply purchase fish that are less desirable or expendable and use them to start the nitrogen cycle. They produce enough waste to get the cycle started. The fish won't survive this process, but the aquarium owner purchases new fish once the cycle is in place.
To read a lot more about starting the nitrogen cycle in an aquarium tank, check out this link.
