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Re: [APD] plants and the nitrogen cycle

 As is standard (in my opinion) for this author, she presents mainly smoke
and mirrors, by referencing facts that are not in dispute.  To my knowledge,
no one has ever said that plants do not uptake nitrogen, and that they, in
general prefer ammonium to nitrate.  None of that is or was in question.
Nitrite uptake by plants is uncommon, that material is as toxic to most of
them as it is to animals, and is as rare in circulation/transport as it is
in animals.  When plants use nitrate, they do reduce it via nitrite to
ammonium - all tightly bond in the cell -that too is undisputed.  I would
like to see references showing that that reduction of the N is as
energy-expensive as the energy gain in bacteria, which she somehow omits -
unusual for that writer, who loves her references.

But none of that deals with or even touches on whether or not bacterial
biofiltration is harmful or detrimental to aquatic plants.  Her personal
example of reducing biomedia in her filters does not in reality enter the
equation.  With care, in any established tank you can move the biofiltration
site at will, from one filter to another (without moving the active media)
or from a filter to tank surfaces.  It does not in any way show that no
bacterial biofiltration is occurring, only that there is no longer a filter
with such - two quite different things.  To leap from that to bacterial
filtration being harmful and actively out-competing the plants for ammonium
is unjustified by the references or by the anecdote provided.  My trials
showed quite the opposite, that the plants easily out-compete the filters,
and that plants use the large majority of the ammonium (released by the
bioload of the tank whether fish, invert, or microbial) before it is
oxidized to nitrate by nitrification bacteria.

I see no justification, and am annoyed by, for her (implied) assumption that
bacterial filters force plants into the more expensive option of using
nitrate. None of her cited references address that area at all.  Most
moderate to brightly lighted tanks I have operated require N addition.  Only
a fool would supplement their tank with ammonia or nitrite at ppm
concentrations, so nitrate is the supplement of choice, unless you use
Seachem's Flourish Nitrogen, which does include bio-available ammonium.
Where is the data showing nitrate use to be so damaging, and why is this so
bad in routine planted tanks with nitrate levels far lower than she cites
from her own tanks?  References, please.

To me, her techniques are a house of cards, supposedly supported by
"evidence" which I have not seen in the material she originally presented in
her book.  I know that she has modified the technique (which is always
allowable based on further evidence), accepting artificial light aw well as
natural, but when she has now allowed mechanical filters (are these
processed in a manner to avoid or block development of biological
filtration?), and UV sterilizers.  There may be more changes that I have not
heard about, but it seems that almost all she has left from her original
book is the shaky assumption that nitrate itself is harmless at high ppm and
routine water changes are undesirable.  Both of those I disagree with very
strongly.  Nitrate alone is far from the culprit it seems to be thought to
be by many hobbyists, but it is still the best evidence we have of overall
pollution and increasing eutrophication.  There has been no demonstration
that her style tanks lack organics in proportion to the nitrate titers, so
far as I have heard.  Has she addressed the matter of certain minerals being
depleted and others increased when tanks are not routinely water changed and
shown those changes to be healthy and beneficial?  Or given any data on the
TDS changes in her multi-month unchanged tanks?  Or ever seen osmotic shock
in such tanks when they do get a water change?

Lot of non-germane data is offered, but precious little from her tanks.  I
suppose that my primary issue with her style is that she is a master
literature searcher, but sorely lacks test data to support her theories.
Using science without science is a contradiction in terms.  It smacks of the
pseudo-science offered by so many commercial products attempting to get us
to buy and use their products despite the lack of any sound or real and
applicable evidence.

I used to be a big fan of science fiction and some fantasy novelists, but I
never tried to apply their anti-matter generators or anti-gravity devices or
time travel or magic talismans to the real world.  Theories are great;
evidence in support of those theories is still required.  Without evidence,
it is a philosophy perhaps, but it will never be more without data.

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