Ok, now I understand. So you're saying that if the bioload doesn't fluctuate, it may only be able to have so much bacteria with the limited amount of ammonia available.
*** Yes and no. Simplistically - yes. Bacteria are animals too that need to breath, eat, metabolize, excrete, procreate, etc. NH3 and NO2 is their food. On average (time-average), there is a "steady-state" concentration of these chemicals in the water and it determines the amount of the "mouths" = bacteria.
Why no? There are other factors. Most importantly, bacteria need oxygen. So, at the same bio-load, the tank with better aeration can have more bacteria in the substrate and in the filter. But bio-load is never steady and neither is BOD Biochemical oxygen demand
http://en.wikipedia.org/wiki/Biochemical_oxygen_demand - they both creep up.
After each feeding, the bio-load increases and the BOD increases because the bio-mass increases (waste, detritus, fish get bigger, etc.) - that's why when the filter and the substrate get dirty or real dirty, there is a danger to kick back/stifle/suffocate all living things in the tank, including the fish and the bacteria and "uncycle" your tank. After cleaning, the bio-mass strongly decreases (= less food) but so does the BOD (= more oxygen), thus largely cancelling out each other.
Chemical composition of water, hardness, salinity, pH, temperature, etc. all have an effect on this but crudely speaking of lesser importance, but nevertheless...
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If that's the case though, wouldn't the only way to get more bacteria be to add more fish therefor increasing the amount of ammonia for the bacteria to eat or could I just over feed the tank to make more detritus which would decompose into ammonia. (Wish I knew all this when I was cycling my first tank).
*** Keeping the above in mind, yes. To get more bacteria - give them more food and more oxygen BUT this process is limited by the surface space on which the bacteria can live (and to which surfaces both food and oxygen have a free, uninhibited access). When there is no more space for them to colonize, giving food and oxygen becomes fruitless.
Analogous "space" thinking applies to dirt - it takes up the space, covers useful surfaces, makes for an uneven flow inside the filter and creates semi-dead and dead spots, and, thus, hinders the access/diffusion of both food and oxygen to the bacterial colonies making them kick back and die off bit by bit as the dirt accumulates. The dirt particles can be settled with bacteria too but since the dirt is not suspended in the water column (= unhindered food and oxygen), this will not have any notable mitigating effect.
That's why I prefer a fishless cycling by utilizing either fish food decomposition or ammonia solutions.
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This and much, much more can be found in various far, far better written articles on tank cycling on the net, in books, etc. Every time I read and re-read them I understand more and/or find something new. The rules of the healthy tank-keeping are simple. Understanding why is not at all. But it is the understanding that helps some the most. Others can just remember the rules and be content
