Thin and polished biofilm huh? How many people have trouble keeping coralline off of this supposed fast flowing surface
High five - this is a true scientific approach - to compare the attaching capabilities between a calcium producing algae with a soft biofilm of bacteria.
The nitrification layer (consisting of chemoautotrophs that's are slow growers) in a biofilm is only around some µ thick because of the facultative aerobes need of oxygen and their faster growth. This is ecology. Even in a polished biofilm (read thin) the anaerobic layer is much thicker than the layer with nitrification. I do not deny that if the biofilm will host bacteria with dentification capability and that they will do that in vitro - if tested. However - will this have an real function in an ecological system as an aquarium? If the theory of continuous nitrification/denitrification is true in reality - that the denitrification capability in the combined biofilm should be higher than the nitrification rate without doubt
Every one owning an aquarium knows that this is not true - the nitrate levels (even if there is no dosing of it) will rise with time in most aquariums - especially in bare bottoms.
However - says some - the poor denitrification rate is cause by lack of dissolved organic carbon (DOC) that can serve as electron donors in the anaerobic metabolism. We add that. Problem should be solved. But - much people have still a problem with rising or not decreasing nitrate levels. Further on - if enough DOC is added - the fast aerobic growth of facultative heterotrophs will outcompete some of the nitrification organisms for space and oxygen - the result is that at least the second step will stop and nitrite will rise.
Fairy tales and it does not work as you think because you are not an scientist will probably be the reply on this. The only thing I can say - study some literature about nitrification in waste water and fish farming.
I´m not a scientist - that´s right - but I have worked with the task to transfer scientific findings into working systems according to waste water treatment and aquatic life supporting system for whole my life - some things have I learned through this journey.
I leave this for @Sallstrom to answer. But interesting to read that´s his more than 10 years of documenting and testing this method in many different systems, small as large can only be dismissed in two sentences by someone who according to his own information has never tested it because it just can not work.....there is no cause and effect relationship between adding nitrate and diminishing cyanobacteria growth in an aquarium. There is no phenomenon to explain.
And he has not tested it on a hobby scale - this is a part of his job - and he is very good in that job
Sincerely Lasse
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