Ca(NO3)2 contains ammonia!?!?!?!?!?!

[hashbaz]

I got some calcium nitrate from Greg Watson. I was worried that I might have too much Potassium, so I did not want to add more from Potassium Nitrate. So I went with Calcium Nitrate instead.

Today when I was figuring out how much to add, I found that the actual Chemical formula is 5Ca(NO3)2*NH4*NO3*10H20 I was a little concerned that the NH4 might cause problems, but I hoped it was not soluble or something.

According to my calculations adding 10ppm of NO3 adds .26 ppm NH4. I put the 10ppm NO3 dose in the tank and measured .25ppm of NH4. :? :? :?

Why is a fertilizer containing this much ammonia sold as an aquarium fertilizer? Or have I missed something?

 

[fish_4_all]

This may be just a shot in the dark but I think you have found another compound formula for Ca(NO3)2. Try here for a better description. It is made both ways but I don't think you are getting the Ammonia formula from Gregs. Email him to make sure by all means to make sure.

 

[czcz]

I *think* the formula you have would be called calcium-urea-nitrate. Here's another page on Ca(NO3)2:
http://www.chemicalland21.com/industrialchem/inorganic/CALCIUM NITRATE TETRAHYDRATE.htm

Calcium Nitrate Tetrahydrate... is prepared by neutralizing nitric acid with calcium carbonate.

Amateur sanity check on nitric acid (HNO3) and calcium carbonate (CaCO3):

2HNO3 + CaCO3 -> Ca(NO3)2 + CO2 + H2O

Your positive ammonia test warrants an email to Greg to find out exactly what he's selling though :/ If you do so, please post what he says. Is it possible to test it at your school?

 

[Apocalypse_Gold]

If you scroll down on fish_4_all's link, there is a calcium nitrate formula that it says is used in hydroponics. This is the only formula for calcium nitrate I saw that would give you the 15.5% nitrogen by weight, which is what Greg's is supposed to be.

 

[czcz]

Do you have reference from Greg on the 15.5%? Would definitely solve which formula it is. His site says its agricultural grade, which would seem to indicate it's the formula containing ammonia

(I know Apocalypse_Gold and hashbaz and most on AA know this, but for others let me reiterate I am not even close to being an expert. Just a hobbyist who somewhat remembers Chem 101/102 from years ago and ket his book. )

 

[hashbaz]

Do you have reference from Greg on the 15.5%?

The bag of powder that I got from Greg is labeled "Calcium Nitrate -- 15.5-0-0"

Is this what you meant?

 

[malkore]

15.5-0-0 is the NPK listing I believe.

If Greg Watson sells it, I wouldn't be too concerned. Check with him, but I'm sure you'll find that it's harmless.
If the NH4 is bound to the rest of the molecule, its not free ammonia, and won't be able to affect fish.

Plus, plants can use NH4 as a source of Nitrogen (which is why it's possible to 'skip' cycling a planted tank if you follow specific procedures).

 

[CompMage]

You have the molicule writen wrong and that is your worry

Calcium agricultural ammonium nitrate 5Ca(NO3)2.NH4NO3.10H20

The NH4 and NO3 are connected and I don't think you can brake one apart without also braking the other apart. Correct me if I'm wrong but if it's written like that and not NH4*N03 it would be completly safe. And with them being that large fish would not be affect by it much.

PLEASE correct me if I'm wrong I'm going by what I can remember and what I found on the net.

 

[czcz]

hashbaz, yeah.

CompMage, in solution it won't go NH4+ and NO3- ?

 

[CompMage]

Shoot

It will brake down. I had a friend confirm this one (Friend has PHD in Non-Organic Molecular Physics) so I take it word as truth with little question.

When it hits the water it will brake down into 3 parts. 1 will be simple water 10, Ca, NO3, NH4 My info from befor was wrong.

Regardless,

The question is calcium nitrate Ca(NO3)2 - (H2O)4 (Very safe for fish)
or
Calcium 5Ca agricultural ammonium nitrate (NO3) 2.NH4NO3.10H20 (Good for plants not fish)

You need to find out what you got your hands on.

Again sorry every one about that.

 

[hashbaz]

I just confirmed my previous results. I took a gallon of RODI water and took out a water sample. I then added .10 grams of the notorious Calcium Nitrate to the gallon of RODI water, and took out another sample.

I then measure both samples for Ammonia. The 1st sample measured 0 ammonia and the second measured just over .5ppm ammonia.

.1gm of 5Ca(NO3)2.NH4NO3.10H20 in 1 gallon of water will yield a concentration of 1ppm NH4. With all the inaccuracies of measuring and mixing, there is a small difference between the expected 1ppm and the measured .5ppm.

I am certain now that the Calcium Nitrate I received contains NH4.

P.S. Thank you, CompMage, for the clarification on the formula.

 

[czcz]

Thank you both.

 

[fish_4_all]

I am just glad I went with KNO3. No headache.