The Science of Cycling a Reef Tank.

The term cycling a tank is derived from the Nitrogen Cycle.  So many of us toss around the term without thinking about what it means.  As an aquarist we all live or die by the nitrogen cycle.  It is the crucial back bone to the system.  a build up of Nitrites or Nitrates will harm or kill fish.  After fully understanding this process you can make a decision about the best way to cycle your tank.


This simple diagram is the basis of the nitrogen cycle as it applies to our tanks.  Excess food, fish waste, dead or decaying plant material all lead to the production of Nitrites which then become Nitrates.   Both are harmful to the system.  This is why we run protein skimmers or filters and use live rock. The algae on the live rock will consume the nitrates.  Canister filters can trap organic material in its media and hold it there thus creating more nitrate problems if not maintained properly.  This is why I do not use one on my tank.   These items are there to remove waste products before they can break down into nitrites.  Overall, there is no substitution for frequent water changes in removing Nitrates