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Nitrogen custom formula problem

Markovzky

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19 May 2021
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4
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Spain
Hi!

I recently acquired nitrogenous salts to fertilize my aquarium, which I mixed in a 500ml pot with osmosis water:
9g Urea
10g Potassium Nitrate
10g Ammonium Sulfate
10g Ammonium Nitrate

However, at the moment of dissolving them, a whitish liquid was formed which I filled to complete the 500ml.

Currently a white precipitate is seen, I shake the content again but after a while a white sediment forms again.

Is my mix spoiled?

What is the white sediment made of?

What will have happened? I consider that I did not exceed the limits of solubility ...

Will it harm my aquarium if I dose with that mixture?

With this mixture I dose 1.5ml / 100lt


Regards
 
Hi all,
Welcome to UKAPS.
Currently a white precipitate is seen, I shake the content again but after a while a white sediment forms again.
Is my mix spoiled?
What is the white sediment made of?
Probably an impurity in one of the salts. Urea and all ammonium (NH4+), nitrate (NO3-) and potassium (K+) salts <"are soluble">. Have you seen the <"UKAPS IFC nutrient calculator">? It tells you if your salt mix has exceeded the solubility limit.

As ball park figures ammonium sulphate has a solubility of about 750g per litre, ammonium nitrate about 1500g per litre, potassium nitrate about 300g per litre and urea about 500g per litre. If you took potassium nitrate as the least soluble salt, that is still 150g in 500 mL and you have 40g, so you are right it isn't solubility.
Will it harm my aquarium if I dose with that mixture?
I'm not worried about the precipitate, but I am a bit worried about the ammonia (NH3) content.

Do you have fish? I know you are dosing a very small amount of fertiliser, but I can't see any advantage to the two ammonium salts?

<"Urea is a lot safer"> than ammonia and all of urea (CO(NH2)2), ammonium sulphate ((NH₄)₂SO₄) and ammonium nitrate (NH4NO3) only add nitrogen (N) as a "useful" element. Potassium nitrate (KNO3) adds potassium (K) as well, so you could add the same amount of potassium and nitrogen purely from KNO3 and urea and you don't need the ammonium salts.

cheers Darrel
 
As Darrel says, likely an impurity either from the Urea or alternatively are you sure your Ammonium Nitrate isn’t Calcium Ammonium Nitrate (CAN), that would be an obvious explanation for precipitation.

Repeat the mix again but dissolve each salt individually before introducing a new salt this way you should be able to identify the compound/s that precipitate when mixed. You could also acidify the mixture to balance out any potential hydroxide formation, did you check the pH of the mix?

:)
 
Como dice Darrel, probablemente una impureza de la urea o, alternativamente, está seguro de que su nitrato de amonio no es nitrato de calcio y amonio (CAN), esa sería una explicación obvia para la precipitación.

Repita la mezcla nuevamente, pero disuelva cada sal individualmente antes de introducir una nueva sal de esta manera debería poder identificar los compuestos que precipitan cuando se mezclan. También podría acidificar la mezcla para equilibrar cualquier posible formación de hidróxido, ¿verificó el pH de la mezcla?

:)

What X3NiTH said was true, it turns out that what I bought as ammonium nitrate, was actually Nitrabor (Calcium Nitrate + Boron) which is not compatible to mix in the same bottle with Ammonium Sulfate, added to that to the endothermic reaction To the mix. all 4 components at the same time, the resulting precipitate is probably calcium and / or potassium (you cannot mix ammonium sulfate with KNO3 either).
Hi all,
Welcome to UKAPS.

Probably an impurity in one of the salts. Urea and all ammonium (NH4+), nitrate (NO3-) and potassium (K+) salts <"are soluble">. Have you seen the <"UKAPS IFC nutrient calculator">? It tells you if your salt mix has exceeded the solubility limit.

As ball park figures ammonium sulphate has a solubility of about 750g per litre, ammonium nitrate about 1500g per litre, potassium nitrate about 300g per litre and urea about 500g per litre. If you took potassium nitrate as the least soluble salt, that is still 150g in 500 mL and you have 40g, so you are right it isn't solubility.

I'm not worried about the precipitate, but I am a bit worried about the ammonia (NH3) content.

Do you have fish? I know you are dosing a very small amount of fertiliser, but I can't see any advantage to the two ammonium salts?

<"Urea is a lot safer"> than ammonia and all of urea (CO(NH2)2), ammonium sulphate ((NH₄)₂SO₄) and ammonium nitrate (NH4NO3) only add nitrogen (N) as a "useful" element. Potassium nitrate (KNO3) adds potassium (K) as well, so you could add the same amount of potassium and nitrogen purely from KNO3 and urea and you don't need the ammonium salts.

cheers Darrel
In the aquarium that I am dosing this mixture has no fish or other inhabitants.

Quería emular la fórmula "Flourish Nitrogen", así que estaba experimentando con esa fórmula.

Tks
 
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