The Nitrogen Cycle in Practice

Generally, water parameter testing isn't practice by the majority of fish keepers. And most do without them, successfully keeping their pets too. Despite the cost, I am a stickler for water parameter testing, as I consider a live fish more valuable than a dead one (and I do overcrowd my fish tanks).

So how does one apply knowledge of the nitrogen cycle into our daily chores in fishkeeping?

Nothing is sterile (or devoid of any living organism) when one starts. Anything you place into the tank, including water will have colonies of bacteria (and other microscopic organisms, too) and the nitrogen cycle should start as long as ammonia is present (it is 'food' or 'fuel' for the nitrifying bacteria).

The most important thing to do in starting a new tank is to increase the nitrifying bacteria population and to provide the 'food' or 'fuel' - and the most practical thing to do in the former is to make this initial population of 'good' bacteria is to increase their numbers. One may ask for some old filter material (or even in-tank substrate) from your local fish stores (but this brings in the risk of acquiring the unwanted organisms that can cause infections or diseases in your tank's occupants). An alternative is the utilization of bacterial preparations (like Sera's Nitrivec) but this entails additional cost and for some hobbyists, are unnecessary or even ineffective. Or add so-called 'starter' fish that will be the main source of ammonia. Just an additional fact, the nitrifying bacteria grow everywhere inside the tank where it is wet, including in the biofilm on the water surface, and all one needs is to provide the food or fuel for survival and population growth in the form of ammonia. Thus in fish-less cycling, ammonia (fertilizer) is added.