Dosing HNO3

[António vitor]

Without plants, usually the pH and KH decreases over time I think it's the HNO3 that make that change, am I right?
being the HNO3 the final product of nitrification...

I do believe that KNO3 would be better (dosing also K) but I also want to decrease my KH and pH a little!

What are the other side effects?
Am I forgeting something?

Regards!
António Vitor

[António vitor]

One more question...
How does the plant captures the NO3-?

trading NO3- with OH- ?
attracting NO3- with some positive ion?
other process?

Regards!
António Vitor

[mad scientist]

HNO3, nitric acid, is a strong mineral acid which as a pH of less than 3. I would strongly discourage you from dosing your tank directly with it. The sudden drop in the pH of your tank might prove to be detrimental for the livestock.

As for nitrogen uptake and its role in plant growth, I found this pdf file on the net which is fairly easy to comprehend.

http://www.back-to-basics.net/efu/pdfs/nitrogen.pdf

Secondly, nitric acid, in its concentrated form can act as an oxidising agent in a redox reaction. Many of the trace elements found in plant fertilisers e.g. Fe, Mo are transition metals and thus exhibit variable oxidation states. This means that they are highly susceptible to oxidation into other states which may be lesser effective in trace elements uptake. The consequences range anywhere from fertiliser wastage to deficiency related complications.

Also, strong mineral acids, especially in the concentrated form, are highly corrosive and might be hazardous if mishandled. The sale of conc. acids is controlled and ithey usually unavailable off the shelves (in Singapore at least). Stick to the common alternatives like potassium nitrate (KNO3) which provides you with not only nitrogen (N), but also potassium (K).

Finally, though seemingly harmless, nitrogen compounds were (and in some countries still are) widely used to make explosives (e.g. TNT). Just a little anecdote: During the world war, the Germans' nitrogen supplies were cut off and they desperately need it for the production of ammunition. This led Fritz Haber, to develop the "Haber Process", the industrial method of ammonia production. Haber went on to win a Nobel Prize for Chemistry (for his contributions to the discovery of the Haber Process, in the spirit of scientific enquiry and advancements, and the betterment of mankind) while the german nutcrackers went on to conquer the rest of Europe with their new nitrogen toys. Life's full of ironies isn't it?

[António vitor]

Thank for your response M. Scientist!
I will follow your advice!

nevertheless I read that PDF, and still have some questions...
ok, the NO3- enters inside the plant with the water, inside it NO3- will be changed into NH2, how this happens?

Regards!
António Vitor

[Plantbrain]

Antonio, do you read Italian? I have an article coming out soon on nitrogen's role. I may also have a similar one in English coming out from TAG.

NO3 is transported via a K+ cation, so adding KNO3 is a good thing. H+'s could/may work also.
From there, once inside the cell, the NO3 will mostly go to the vacuole for storage and then reduced(a reductase enzyme) to NO2 and then quickly reduced to NH4 inside the chloroplast. Once in this form, the NH4 is converted to Glutamine via GS and a GOGAT enzyme and off to the other pathways for amano acid formation.

There are a couple of forms of GS which are in the chloroplast and another one out in the cytosol of the cell. NH4 is taken in as well and this allows it to be converted to Glutamine quickly without a trip to the chloroplast.

Plants are lazy, they don't do more work than they have to.
Sort of like people

NO3- + 8H+ + 8e- ---> NH3 + 2H2O + OH-

It takes 8 electrons to do this conversion to reduce NO3 to NH3(NH4+)

If you want to soften the water, RO works well. A number of people used H2SO4 to destroy the KH in the past. Messy, nasty way to do it if you ask me. Doesn't help plants one bit either.

Here's my hardwater tank witha GH of 24 and a KH of about 11:
http://www.picturetrail.com/gallery/...d=1473668&

I also keep rummy noses and cardinals etc which all did well.

Plants want CO2 and nutrients, not soft water.
Best way to decrease the pH and get the CO2 for the plants.

Use Ergeria najas or Hydrilla for lowering the KH if you have a non CO2 plant tank. Works great.


Regards,
Tom Barr