Ammonia(NH3) NH3 otherwise known as ammonia is produced from fish waste, old uneaten food, dead plant matter and from the fishes gills. Ammonia is first chemical compound produced in the nitrogen cycle and also the most toxic to fish. Nitrosomonas bacteria will convert this into less poisonous nitrite. Nitrite(NO2) Nitrite is the second chemical compound produced in the nitrogen cycle, it is also fairly poisonous to fish. Nitrite is consumed by Nitrobacter bacteria and converted into nitrate. Nitrate(NO3) Nitrate is the final chemical compound produced in the nitrogen cycle, Although nitrate isn’t considered toxic at low levels, at high levels e.g.(50ppm and above) it is said that it can damage fish health and stunt the growth of fish especially young fry. Some of the ways to remove nitrate from a aquarium are. By doing a water change which will dilute the nitrate, plants use nitrate as food, there are denitrifying chemicals available from a local fish shop and denitrifying coils can simulate anaerobic conditions where denitrifying bacteria can grow and consume the oxygen in nitrate. Leaving the excess nitrogen to escape harmlessly into the atmosphere, but these coils can be hard to control and can produce dangerous poisonous compounds if not run correctly.

Maturing Your Filter
New aquarium setups should always be matured before fish are added. There are several ways to begin this process. Fishless cycling, Cycling with fish, Cycling using maturing products purchased from a local fish shop or Seeding filter media with old media from an established aquarium. Fishless cycling is considered more humane than cycling with fish because ammonia and nitrite are poisonous to fish, but on the down side fishless cycling will take a lot longer to mature a filter than cycling with fish method, fishless cycling can take at least three to four weeks to mature the filter. Cycling using maturing products can speed up the fishless cycling method, but it means spending even more money on these products. If your lucky enough to know someone with an already established aquarium and they are willing to give you some old filter media. You can use the seeding the filter method which I believe is the fastest method of all. At first ammonia will start to build up in the water The growing colony of Nitrosamines bacteria will start to convert it to nitrite but only very slowly at first. The ammonia will peak and start to come down as the colony of Nitrosomonas bacteria grow larger. After that nitrite levels will do the same thing. Nitrite is consumed by Nitrobacter bacteria and converted into nitrate, then the ammonia and nitrite levels will go to zero. At this time it is now safe to put in a few fish and wait a couple of weeks until your confident the nitrifying bacteria can handle the bio-load in the aquarium, Slowly build up your stock of fish. Adding fish should be done in gradual stages and not all in one go, because the nitrifying bacteria in your filter just wouldn’t be able to handle a sudden large rise in bio-load, ammonia and nitrite levels would sky rocket which would probably lead to the early deaths of a lot of your newly purchased fish.

Maintaining Your Filter
As time goes by your filter is going to require some maintenance to keep it working properly. Sponges in your filter will start to become clogged with dirt. So they will need to be cleaned out. Once every month or so, but not in tap water as this contains chlorine which kills bacteria. Only in old tank water left over from a water change. Gently squeeze the sponge in the water till most of dirt has come out then place back in the filter. Only 50% of the sponges should be cleaned at any one time and left for a week or so, before cleaning the other 50% of the sponges doing this reduces the chances of killing off the bacteria by handling the sponges. This is also true if your replacing old worn-out sponges, only replace a maximum of 50% of the media at any one time.