Chemists??? need water help here!

[Grinder12000]

I'm trying to get info about my water and it's like pulling teeth.

So far I have

Calcium = 11 mg/l
Magnesium = 6.1 mg/l

How does mg/l compare to ppm

Next question once I get that tiny bit of info!

 

[jfenton78]

Getting your local water report should not be hard. Just give your local municipal water department a call and ask for a water report. They generally have them available for pickup. If you live in a rural area, you have to send samples off to be tested. A good place that people recommend is Ward Labs.

As for the units in water 1 mg/L is equal to 1 ppm. This can vary if for other liquids. But this is the general rule.

If you have questions about what each ion mean to brewing applications look over water sections in either How To Brew or designing great beers. Hope this helps. good luck.

Jeff

 

[Grinder12000]

I'm reading that and it is not making sense. His numbers are not adding up correctly when comparing them to his nomograph.

(Ca / 20 + Mg /12.1) * 50 = CaCo3

So for LA he has

(70/20 + 30/12.1) = 120

pg 162

 

[SteveG]

So in the concentrations we are talking about here.. 1ppm IS 1 mg/L

1mg/L = 1g/ million cubic cm's

1g/million cubic cm's * 1 cubic cm / 1 gram (using density of water) * 1part/million parts = 1ppm



EDIT: at least that's how I remember it from gen chem

 

[Grinder12000]

So 11mg/l = 11 ppm?

 

[ChemE]

So 11mg/l = 11 ppm?

Yep, you got it. A liter of water weighs 1 million milligrams (1000 grams for you folks playing along at home) so 1 milligram of water is 1 of 1 million parts comprising the liter. Thus, 1 part per million, thus 1 ppm. So 1 mg/L is 1 ppm.

 

[SteveG]

while that is not EXACT, it is a close enough approximation when talking about a solution that is this dilute. We are talking about salt concentrations that are on the order of mg/kg (which is ppm... 0.001g/1000g) Thus we can use the density of 'pure' water in the calculations.

EDIT: Yeah, what ChemE just said... I'm a slow typer.

 

[ChemE]

while that is not EXACT...

Hehe, I know. I had to fight the urge to be overly-anal (an engineer) as well!

 

[Grinder12000]

I don't think I asked for the right thing - I asked for Ca, Mg and bicarbonate, not Alkalinity