Cycle Question

I am not sure what you mean by "make it harder", but if you are
implying that high NH3 levels kill the nitrobacter than what is the
ED50 for this? Furthermore, is the ED50 less than the maximum
concentration of NH3 that is normally reached during cycling? Is this
something you found out after doing some research on your own? Heehee
hee heee, snicker!

I've heard this claim before--Wayne Sallee did not just pull it out of his
ass through personal or unscientific observation. I believe there is
research out there to back it up.

Than you must know what he means by "real high ammonia levels makes it
harder on the bacteria"?? I sure don't What do you think he means by "make
it harder"?

I would love to read some literature on this phenomenon.


I am uncertain myself if there is a direct relationship between the levels
of free ammonia and the efficacy of nitric bacterium

I am not aware of any literature that claims that high concentrations of
ammonia (within the realm of a normal cycling) decreases the efficiency of
nitrobacter to metabolise NO2-.

Read the link I provided (first one I came across, I'm sure there are
others) under the heading nitrifying bacteria on the relationship between
NH3 and microbe population. They state (as I have) that the concentration
of the nitrifiers (bacteria) depends on the rate (increased rates yield
increased concentrations) of NH3 production. The faster the rate (and thus
the greater the concentration) the higher the population of both microbes
(nitrobacter and nitrosomonas).

http://www.cci.unl.edu/Teacher/NSF/C...thotrophs.html

or an indirect one in
which the relationship is as simple as the fact that the conversion of
nitrite into nitrate requires more oxygen and more energy than the
conversion of ammonia into nitrite and therefore nitrous bacterium have
easier access to available oxygen.

You are missing the entire point as to why these bacteria are metabolising
NH3 and NO2- in the first place. This process of converting NH3 into NO2-
and NO2- into NO3- does NOT consume energy it PRODUCES energy. This is how
these bacteria produce their metabolic energy (ATP).

I'm not sure which bacteria (nitrobacter or nitrosomona) consume the most
o2.

Hopefully the previous poster can
produce some referenced material to clear this up.

Doubtful

"Stoutman" .@. wrote in :


between NH3 and microbe population. They state (as I have) that the
concentration of the nitrifiers (bacteria) depends on the rate
(increased rates yield increased concentrations) of NH3 production.
The faster the rate (and thus the greater the concentration) the
higher the population of both microbes (nitrobacter and nitrosomonas).

You're incorrectly inferring that a high rate of production means a high
concentration of free NH3. The article is saying that bacteria will
increase their population density in response to an increase in the
availability of their food source. This is natural and to be expected.

Here's the quote:

"The concentration of nitrifiers depends upon the rate of NH3
production in the surrounding environment. The faster the rate, the higher
the population of microbes."

This says nothing about the concentration of measurable NH3 or the effect
the amount of measurable NH3 has on the overall conversion of NH3 into NO3-
in a new system, only that in an established system were the production of
NH3 is high the population of bacteria found using it as a food source will
also be high. In either an established low rate or a high rate environment
the amount of measurable NH3 is likely to be the same, ~0 ppm. We are
talking about fledgling cultures while the article is talking about mature
ones.

Here's another quote for you... I managed to dig it out of an article
published in the Plant and Soil journal in 1972.

"Summary: ...ammonium concentrations in excess of 200 ppm N
reinforced population imbalances conductive to accumulation of nitrite over
time in mixed cultures of Nitrosomonas europaea and Nitrobacter agilis.
Nitrate production proceeded at a low, linear rate characteristic for a
nonproliferating population, indicating a bacteriostatic effect of ammonium
or free ammonia on growth of Nitrobacter rather than an inhibitory effect
on nitrite oxidation."

I guess it is a direct effect after all.



You are missing the entire point as to why these bacteria are
metabolising NH3 and NO2- in the first place. This process of

This point is moot to the topic being discussed.

Either way it was merely a misuse of terms on my part. I fully understand
WHY nitric bacteria do what they do. I was not referring to a greater
demand for metabolic energy. A greater need for resources would have been
a more appropriate term to use in that context.



I'm not sure which bacteria (nitrobacter or nitrosomona) consume the
most o2.

I'm not sure either; it was just a guess or a suggestion at a possible
reason for lack of a documented explanation at the time.



Hopefully the previous poster can
produce some referenced material to clear this up.

Doubtful

What is the point of such a glib attitude in a community where the aim is
the sharing of experience and knowledge?

Is it merely to polish your own ego?