# Calcium nitrate - need some advice



## dmachado (7 Mar 2015)

Hello, I have available some calcium nitrate with the formula 5Ca(NO3)2.NH4NO3.10H2O, which seems to be 19% CA, 15,5% nitrogen including 1,1% ammonia.

Does it add ammonia in dangerous levels? I want to combine it with KNO3 to add also calcium to my dosing.

If so, why is it used at petalphile?

Thank you.


----------



## ceg4048 (7 Mar 2015)

Hello,
              Calcium Nitrate does not contain ammonium. The product you list is Calcium Ammonium Nitrate (hydrated). The molar mass of this compound is about 1081 grams/mole. Ammonium has a molar mass of about 18 grams/mole, so that's just over 1.5%. Therefore 10 grams of the compound will add about 1.5% of 10 grams of NH4, which will be about  0.15 grams (150 mg).

Adding 150mg of NH4+ to 100L of water will yield 150mg/100Kg = 1.5ppm NH4+
This can be bad or not-so-bad depending on a lot of things, such as the pH of the water, total plant mass, temperature and so forth.

There are a lot of options to add calcium to your water and you may not even need to add Calcium if you live in a hard tap water area. You can just add a few teaspoons of coral sand or oyster grit to your filter and then forget about it. I don't see any reason to use this product unless you are getting it much cheaper than more commonly available Calcium sources.

Cheers,


----------



## dmachado (9 Mar 2015)

Thanks for the explanation, Clive.

A small amount of ammonium may not be very harmful with a big plant mass, but I know toxicity rises fast with higher pH and higher temperatures.

I checked my tap water reports and they show Ca at 36mg/l and Mg <4mg/l, so I am guessing only Mg should be added.

What would be the plants Ca ppm uptake, can you give an idea? Would they be depleting the Ca in a few days? I know it will be related with the plant mass, of course.

Regards.


----------



## ceg4048 (10 Mar 2015)

Hi,
 Well, again, 36ppm of Ca++ and 4ppm of Mg++ are enormous amounts and these values are enough to last a lifetime. These are micronutrients so you only need microscopic amounts. 

The only time you should even think about this is if you are using straight RO without remineralizing (which is a bad policy anyway) or if your local municipal water is too soft and you did not remineralize.

There is no possibility whatsoever of depletion of Calcium (Ca++).
High Ca++ levels in the cytoplasm of the plant would be extremely toxic, therefore, the plant develops some very restrictive Ca++ uptake mechanism to counter the threat.

Ca++ is very mobile within the leaf but it NEVER travels from the leaf. Over the life of the leaf Ca++ never becomes depleted but only ever accumulates. All of this is self regulating, so if plants are in a high Ca++ environment they simply restrict the Ca++ uptake, while if they are in a low Ca++ environment then the uptake restrictions are relaxed and then it's only a matter of time before sufficient levels of Ca++ accumulate.

So, as is typical of advice found in The Matrix, you are trying to solve a problem that does not exist, and in doing so could potentially cause many more problems than you would ever solve.

If I were you I would immediately forget about adding Ca++ and Mg++ (and definitely forget about adding it via ammonium salts) because you already have more  Ca++ and Mg++ than you need, which also is absolutely fine. If you are experiencing a problem with plant health and if someone told you that you needed to add Ca++ and Mg++ then you should ignore that particular advice, as the root cause definitely lies elsewhere (most likely with CO2 faults).

Cheers,


----------

