Water Hardness

[ricardo]

Quick question.

I sent an email to Mitch Steele of Stone Brewing asking about their water profile and he replied saying that in the past before they started using salts it was 70 ppm Calcium with 100 ppm hardness.

How can this be when the hardness on 70 ppm Calcium alone is 175 ppm, am i missing something?

 

[manticle]

Was he referring to temporary or permanent?

 

[ricardo]

Was he referring to temporary or permanent?

he said total hardness which i believe is permanent

 

[manticle]

Permanent hardness is a measure of the total calcium and magnesium hardness combined (relating to them binding with sulfates) and can be expressed in different ways. CaCO3 is common but there are others*.

In order to answer your question better, it would be good to get some more info. What exactly was asked and what exactly was the answer?

How was Mitch expressing hardness? What is the Mg2 hardness? etc.

*I have to double check this

 

[ricardo]

Permanent hardness is a measure of the total calcium and magnesium hardness combined (relating to them binding with sulfates) and can be expressed in different ways. CaCO3 is common but there are others*.

In order to answer your question better, it would be good to get some more info. What exactly was asked and what exactly was the answer?

How was Mitch expressing hardness? What is the Mg2 hardness? etc.

*I have to double check this

Hi Manticle, just sent you a PM

 

[manticle]

Total hardness is the sum of temporary and permanent hardness. I thought I had this stuff in my head but I'm going to need to check some sources and get back to you so I don't lead you astray. Calcium and magnesium will bind with other compounds in different ways and affect hardness and alkalinity differently.

 

[manticle]

I'll keep looking but I can't work it out - mainly because the email is so short on details. He might have dropped a digit, he might be talking about total hardness after boiling but I'm not sure and don't want to write hypothetical stuff based on nothing.

Have you got their exact profile as other ions will be of interest as well?

 

[ricardo]

It's a bit strange isn't it as the figures for Stone post treatment in their book are;

Calcium 30
Sulphate 85
Magnesium 12
Sodium 40

 

[mabrungard]

Interesting. I just conversed with Chris White a day ago and he mentioned that his San Diego water had 160 ppm Ca and they use RO water for their yeast production. I understand that there are multiple water sources for San Diego, so it should not be a surprise that there is a discrepancy. However, the OP is correct that you can't have 70 ppm Ca and then only have 100ppm hardness. It would be 175 ppm hardness as CaCO3 and it makes no difference regarding temporary or permanent hardness. That aspect has to do with the anions associated with the Ca and Mg.

 

[ricardo]

OK I think I may have worked it out. In Mitch Steele's IPA book he states that Stone's municipal water is 300 ppm total hardness but after being treated with RO it is 100 ppm. This could be say Calcium 20 ppm and Magnesium 12 ppm. It maybe that they then add Gypsum to bring the Calcium up to 70 ppm? A total guess as I'm not sure if RO strips all of the minerals out or leaves some behind?

 

[Crusty]

OK I think I may have worked it out. In Mitch Steele's IPA book he states that Stone's municipal water is 300 ppm total hardness but after being treated with RO it is 100 ppm. This could be say Calcium 20 ppm and Magnesium 12 ppm. It maybe that they then add Gypsum to bring the Calcium up to 70 ppm? A total guess as I'm not sure if RO strips all of the minerals out or leaves some behind?

RO strips it out completely, nothing left behind ( total dissolved solids ) = 0

 

[ricardo]

RO strips it out completely, nothing left behind ( total dissolved solids ) = 0

That's what I thought but in the book it states "use municipal water (-300ppm hardness) that is carbon filtered and reverse osmosis treated to reduce hardness to 100 ppm.

 

[mabrungard]

No, RO does not strip all ionic content out of water. Up to 10 percent of some ions (typically mono-valent ions) make it through the membrane into the product water. As much as 4 percent of the di-valent ions make it through the membrane. So there is a bit of ionic content in the product water. TDS of RO is dependent upon the ionic content of the raw water and the type and condition of the membranes. In many cases, the TDS of a properly operating RO unit will be below 50 ppm.