[hooman53]

hi ,i am ahorticulturist who wants to calculate chemicals in grams
based on the mM weigh which i got from labratory.how i can do that please
advise
NH4 1.25mM from NH4NO3
K   8mM from  Kno3
Ca  4mM from Ca(no3)2
Mg  1.375 from Mgso4-7H2o
No3 16mM from  Kno3 or Nh4No3
thanks

[english]

Is this millimolar or micromolar?  What are the volumes of these concentrations?

[hooman53]

Is this millimolar or micromolar?  What are the volumes of these concentrations?

these are milimolars and volumes is one litre

[Sam (NG)]

All of your compounds have 1 mole of the required ion per mole of compound, therefore, you just use the following equations:

no. moles = molarity (M) x volume (litres)
mass = no. moles x molecular mass

I get for 1 litre of water:

1.25 mM NH₄⁺ = 0.100 g NH₄NO₃

8 mM K⁺ = 0.809 g KNO₃

4 mM Ca²⁺ = 0.728 g Ca(NO₃)₂

1.375 mM Mg²⁺ = 0.339 g MgSO₄.7H₂O

16 mM NO₃^- = 1.281 g NH₄NO₃ or 1.618 g KNO₃

[Sam (NG)]

but i haou ve to balance cations and anions i mean when you add nh4no3 you add nh4 and no3 toghether or when you add kno3 you add no3 and this gives us more no3 that we desire in one litre concentration
 

I'm not quite sure what you are saying here, but i think you are saying that you want to get the correct cation concentrations without exceeding the specified concentration of nitrate, while still using the compounds you've given.

In order to get the cation concentrations you have requested, the minimum nitrate concentration you can create is a 17.25 mM solution, which is created just by adding the amounts of the salts for ammonium, potassium and calcium cations i have quoted to one litre of water.

In order to get round this you will have to use a different salt for one of the cations (one that doesn't contain nitrate).  If you use Ammonium sulfate for the ammonium cation, then you can get the nitrate concentration down to 16 mM, but this will change the pH balance of the solution.  If you use ammonium sulfate, only use 0.0826 g per litre for 1.25 mM.

[hooman53]

thanks, i can do that when i add micro elements to the solution

[hooman53]

ok thank you very much
bye
Houman

[Sam (NG)]

this is the  recipe that i got from labratory to prepare a nutrient solution,i will thank you if you help me to calculate salts
Ec=2.2
NH4 1.25mM                             
ca      4
mg     1.375
no3    16
so4 1.375
h2po4 1.25                                 ph should be between 5.5 to 6.5
k        8
fe 15 micro molar
mn 10 micrmolar
Zn  5 micro molar
B    25 micro molar
cu  .75 micro
Mo  .5  micro
 

I need to know the salts that you are using for each of the constituents.

[Borek]

I need to know the salts that you are using for each of the constituents.

Some creativity, man

First try to balance cations/anions already present. Then use chlorides for the rest.

[hooman53]

Ec=2.2
NH4 1.25mM            Nh4No3                 
ca      4                   5(ca(no3)2.2H2O).NH4NO3
mg     1.375             MgSO4.7H2O
no3    16                 calcume nitrate or potassium nitrate
so4 1.375                aluminium sulphate
h2po4 1.25               super phosphate0.20.0 or triple super phosphate0.45.0                 
k        8                    Kno3
fe 15 micro molar        chealate iron sequestren330
mn 10 micrmolar          Mnso4
Zn  5 micro molar         Znso4
B    25 micro molar       borate ammounium ,Borax
cu  .75 micro                Cuso4
Mo  .5  micro               molybidate ammounium

irrigation water that i gonna use ,has these contents
EC :4
,PH :6.8
, HCO3 :2.7me
,   CL :.6me
 , SO4:  1.1me
 ,  mg: 2me
, Na:  .56me
 k:1mg
sorry i know it is a time taking task but you can help me more than you think about it   

[Sam (NG)]

I need to know the salts that you are using for each of the constituents.

Some creativity, man

First try to balance cations/anions already present. Then use chlorides for the rest.

I mean't the salts that he has available, seems that they are mostly sulfates and nitrates.

Hooman, what do the numbers "0.20.0" and "0.45.0" mean?

what is "me", also what is "Ec=2.2"?

[hooman53]

sam all of them are available,
 means N.P.K,20 percent P,45 percent P

[Sam (NG)]

                 
5(ca(no3)2.2H2O).NH4NO3

If you use this you will have 4mM ammonium ions without adding anything else.

[Sam (NG)]

sam all of them are available,
 means N.P.K,20 percent P,45 percent P

Is that percent mass Ca(H₂PO₄)₂?

[hooman53]

 mili equivalent,when you add these slats together you will expect this EC2.2