[APD] RE: Nitrogen

["Thomas Barr" <tcbiii at earthlink_net>]

>  > Not the NH4.
>  > Something caused a back up of the NH4 uptake.
>
> Ok. I assumed mistakenly that nitrogen would only be present in a water
> column in the form of NH3, NO2 and NO3.

NH3/NH4 is a pH based ratio.
Plants and algae use NH4. The lower the pH, the more that exist as NH4.
Plants will reduce the NH3 to NH4 at some stage. 
It's on the krib somewhere or you can find the references on line at a
chemistry site.
It the context here, it does not matter much. 
Think NH4 and plant nutrient that can at high levels(not that high,
typically unmeasurable with most test kits), think NO3 plant nutrient that
does not cause algae blooms. 

>  > It's plenty for the algae(NH4 and only a small amount is needed) but
>  > not enough total N for the plants.

> Does it mean that plans would consume NO3, NH3 and NH4 but the rate of
> consumption of NO3 is higher then for NH3/4?

The speed at which the NH4 is produced is slow and steady
generally/hopefully. Ideally it will be used up as fast as it's produced. 
So it's gone before you can test for it.

But plants need far more N than NH4 alone can supply at high light/CO2. It
does not hurt to have morderately high NO3 levels in a non CO2 tank or very
low light CO2 enriched tank either, but it's not mandatory either if you
have a good fish load and feed regularly. 

> Does this mean that algae (green water one) prefers (consumes faster) 
> NH4 or it takes in only NH4 and alike, not NO3? 

NH4 induces the bloom(causes the normally inactive spores to activate),
once established, the adult algae are very tough to get rid of.
The adults will use NO3 as well as NH4 like "adult" plants(All plants in
relation to algae are huge "adults").

The reason for my 
> question is that you want to maintain NO3 slightly above zero, so as not 
> to starve higher plants, isn't?

Not slightly above zero, there's not need for such close tolerances,
5-20ppm seems fine. 
You are getting close to bottoming out less than 5 or so ppm.
That will cause algae as well.

There's a simple solution to maintaining all these nutrients, don't worry,
see below. 
It's rather easy and simple.

> Pardon my ignorance, but where ( or from which product ) does KNO3 comes 
> from? For example potassium supplement by Seachem claim to contain 
> soluble K20.

KNO3= generally folks use stump remover, it's 99% KNO3 in most all cases.

www.gregwatson.com sells everything you need as far ferts and you'll note
that it's very cheap.

Get: 
KNO3
KH2PO4
Traces or buy TMG or Flourish(or other decent brands, these two have been
my favorites over the years).

> So, basically you are advocating implanting new tank with bacterial 
> culture from established aquarium. 

Yep.

Still, I don't exactly understand 
> which bacteria eats NH4 and how does it fit in the nitrogen cycle. 

They oxidize NH4 => NO2 then another set of bacteria oxidize this to NO3.
They do not have much role as the plants take off, but intially they do
help to balance a new tank out.

There are other cycles going on and I'm not going to get into it because
it'll confuse you now.
Wait for later for that.
 
> Perhaps then, someone could point me to a more developed nitrogen cycle 
> diagram than simple
> NH3 -(bacteria)-> NO2 -(bacteria)-> NO3 -(consumed by plant)-> plant 
> -(fish eat plant)-> NH3

Well if it was a self contained cycle, yes.
But you prune and remove plants(which removes N/nutrients), do water
changes(which removes some N/nutrients)
The diagram I sent to TAG is fairly straight forward and applies to a
wetland plant.

>  > As logn as you can amaitain that during the day peroid and not let it
>  > drop off later in the week etc between brew changes in the CO2, your
>  > are fine. If not, then you will get algae.

> Why? How will this affect level of NH3/4 if I have very little fish in it?

Poor CO2 causes 90% of all algae issues I've ever seen.Slows down NH4
uptake by the plants, this lower CO2 does not influence algae spore
though.Some seem to do better when the CO2 varies or is slightly lower than
15ppm or so.

High CO2 will drive plant uptake rates faster and keep plants non limited
in terms of CO2. Carbon is 40%+ of dry weight plant biomass.
Some algae are induced by varying the CO2 levels from high to low to high
etc.
Algae and plants both prefer CO2, but plants need far more CO2 than algae. 

Again, a bit like the NH4 vs NO3 thing.
Green tends to come back repeatedly in tanks with poor CO2.
Trust me, your tank will grow much better if you do this. 
For now, that's all you need to know about CO2, add 20-30ppm during the day
period.
You are not going to learn everything in a couple of post. 
Try some things first.

> However, I've seen plenty of tanks which did not seem to have UV or 
> diatom filters and yet had crystal clear water.

With 5w/gal and DIY CO2?
I never had any Green water till I added NH4. 
More light and poor varying CO2 levels will sure help Green water. 
Make sure the pH and KH are giving you 20-30ppm of CO2. 
The pm time will have the least amount of CO2 so that's the main one to
check.
I gave you the reason why, there are many things that you could have done
to influence the NH4 uptake and caused a back up of this to induce the
algae.
You can answer that better than I can. 

>  >>    Thus I'd like to supply additional nitrogen to a higher plants
>  >>only, which means adding something to a substrate.
>  >
>  > No, this method does not work. The algae are not limited while you are
>  > able to supply the nutrients to the plants.
>
> But wouldn't stimulating higher order plants help them to consume more 
> NH3/4 and thus make it a limiting factor in algae grows?

Stimulating them helps sure, but it does not matter where you do this is
the point here.
You gain nothing by placing the fertilizer in the substrate in terms of
algae control.
It can **possibly** help **some** plants do better since the plant does not
have to transport the nutrients down to the roots from the shoot, some
plants seem to do better with some Fe in the substrate in terms of color
and general health, a constant source of Fe to the roots in some species
does seem to help.
NH4 is the only limiting nutrient form I know of for plants/algae.
Everything else can be in excess and not cause algae (generally, this is a
wide range though). 
The small amount of N in the form NH4 really makes a difference in a
controlled a study, I've not seen it does much in practice.
I've messed with it for a few years.  

> Ok. Do you know by chance what is exactly in Seachem Flourish Nitrogen?
> They do mention that it is derived from urea, but claim on the same page 
> that "no free ammonia is released because the ammonium in Flourish 
> Nitrogen? is complexed and unavailable until utilized by the plants.".

I'm a biochem guy, not an organic chem guy, ask Greg, it's his thing, I
don't use it. You can ask SeaChem directly. 
It does not cause an algae bloom as far as I know.

I don't think there's a lot of it(NH4) and if it is complexed, there is a
cost associated with that so it's not as "rich" as NH4 from fish waste etc.
But it seems like a decent product, I use fish waste and KNO3, I do not
need NH4 more than that.
I grow plants just fine without hardly any NH4/no fish load at all and use
KNO3 exclusively.
I cannot tell the difference in practice using that NH4+NO3 vs NO3 alone.  

> Could you elaborate on location of your article?

The Aquatic Gardener(TAG) magazine

And here is the fert routine that makes life easier:
http://www.aquatic-plants.org/articles.html

Under "fertilization"

regards, 
Tom Barr

> Dmitri Priimak



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