Hi all,
It is difficult to quantify, because there are a lot of potential variables.
We have to make some assumptions and even a microscope isn't very useful. The recent findings of a whole kingdom of unknown nitrifying organisms was done by <"
looking at microbial RNA for Ammonia oxidising genes">. This was how people found COMAMMOX
Nitrospira and the Ammonia Oxidising Archaea (AOA) in Aquarium filters. What <"
they didn't find"> were the ammonia oxidising bacteria
Nitrobacter etc which were thought to be responsible for aquarium nitrification.
The <"
nitrifying micro-organisms"> are potentially anywhere there is a surface and oxygen as "a biofilm". In a <"
nutrient rich"> highly oxygenated environment the "surface" could actually be other microbes where <"
microbial flocs may build up">.
The exact nature of the <"
microbial assemblage"> will depend upon the <"
amount of oxygen"> and <"
the supply of ammonia">.
It is all down to oxygen, so if you don't have plants the substrate is likely to be largely de-oxygenated and that will limit nitrification. If you
<"have plants"> then the situation is different in that a larger area of the substrate will be oxygenated and the potential for nitrification increased.
Plants modify the substrate because their roots are leaky structures and <"
leak both oxygen"> and <"
carbon compounds">.
This is from: <"
Myriophyllum aquaticum Constructed Wetland Effectively Removes Nitrogen in Swine Wastewater">.
cheers Darrel