Check on whether or not to Add Sodium Sulfate

[Jeff Miotke]

Sure could use some help. Received my first ICP test and noted that Na and S were low. I have been dosing BRS 2 part Calcium and Alkalinity and not dosing the Mg part as Mg was always reading high with my test kits.

To raise S by 100ppm I calclulate that it will take 101.4g of Sodium Sulfate Anhydrous for 500L of water using previous information in a post by Randy. Is this correct?

What would the corresponding increase to Na be?

Thanks.

Here is the results of the ICP report:
Ag Silver -0.02
Al Aluminum 0.04
As Arsenic 0.02
B Boron 4.62
Ba Barium 0.02
Be Beryllium 0
Br Bromine 56.25
Ca Calcium 401.12
Cd Cadmium 0
Ce Cerium 0
Cl Chlorine 19307.66
Co Cobalt 0.01
Cr Chromium 0.01
Cu Copper 0
Fe Iron 0
Ga Gallium 0.93
I Iodine 0.03
K Potassium 408.15
La Lanthanum 0.01
Li Lithium 0.2
Mg Magnesium 1351.89
Mn Manganese 0
Mo Molybdenum 0
Na Sodium 9843.56
Ni Nickel 0
P Phosphorus 0.04
Pb Lead 0.02
Rb Rubidium -0.08
S Sulfur 831.77
Sb Antimony 0.01
Se Selenium 0.01
Si Silicon 0.08
Sn Tin -0.08
Sr Strontium 5.17
Ti Titanium 0
Tl Thallium -0.08
U Uranium 0.13
V Vanadium 0
W Tungsten 0.01
Zn Zinc -0.01

 

[Randy Holmes-Farley Verified Community Expert]

That will boost the salinity substantially. It is OK to do it, but go slow.

Lack of dosing the magnesium is is likely why the sulfate declined.

 

[Randy Holmes-Farley Verified Community Expert]

The calculation is not correct. I'll rework it

 

[Randy Holmes-Farley Verified Community Expert]

Sodium sulfate (mw = 142) is 22.5% sulfur (mw = 32) by weight.

If you want 100 mg/L in 500 L, you need 100*500 = 50,000 mg sulfur, or 222 g sodium sulfate.

222 grams of any salts added to 500 L will boost salinity by 222g/500 L = 0.44 g/L, or 35 ppt to 35.44 ppt (sg = 1.0264 to 1.0267). That's an increase of 1.3%, so when you drop it back to your normal salinity, everything will decline by 1.3% except

 

[Randy Holmes-Farley Verified Community Expert]

The sodium increase will be about 144 mg/L.

 

[Jeff Miotke]

Sodium sulfate (mw = 142) is 22.5% sulfur (mw = 32) by weight.

If you want 100 mg/L in 500 L, you need 100*500 = 50,000 mg sulfur, or 222 g sodium sulfate.

222 grams of any salts added to 500 L will boost salinity by 222g/500 L = 0.44 g/L, or 35 ppt to 35.44 ppt (sg = 1.0264 to 1.0267). That's an increase of 1.3%, so when you drop it back to your normal salinity, everything will decline by 1.3% except

Ok awesome. So glad I got your help on this. So one follow up question then. So wouldn't I want to keep the Salinity at the new level so that everything is in a good range? Is it possible to calculate the salinity based on the ICP test?