I just got a water report from the city I live in I have a total hardness of 45 ppm Calcium 20 Sodium 40.8 Magnesium 4.4 Chloride 74 Sulfate 25.8 it didn’t list carbonate but based on the total harness i’m estimating around 20 I’m trying to match Edinburgh water and I can get close with gypsum and a little epsom salt calcium carbonate would bring the calcium perfect and the carbonate close. My question is the carbonate can have undesirable affect on the mash. Should I just mash with the gypsum and add the other minerals to the boil? I’ll be mashing mostly pale malt with 10% munich and 10% melandoin malt.
Bicarbonate and hardness aren’t really related. Do you know the alkalinity?
No the report I was sent was for contamitnants and quality but the water is fairly soft I dont get any precipitate after I boil and soap lathers easily. I lived in Munich for four years and I rememger the mineral ring that would develop in the tea kettle. I don’t get anything like that
No, your alkalinity mist be around 270 ppm as CaCO3. Which is quite a lot.
I got this by assuming that the only missing ion is bicarbonate, which is generally the case. Without that ion your water report is severely imbalanced (more (+) ions that (-) ions). You don’t see much precipitate b/c your calcium is fairly low and magnesium doesn’t precipitate through boiling. What is odd with your water is that this is the first time that the magnesium hardness is way higher than the calcium hardness. This is not impossible but unusal.
Kai
Kai, how are you estimating alkalinity using only the total hardness? My understanding was that alkalinity is influenced only by carbonates.
It seems like his Ca hardness is higher than Mg too: 2.520 > 4.14.4. Or is my understanding of all this stuff that far off?
The total hardness is less than the Ca + Mg too. Are these averages?
Yes, you are correct. I misread the OP as 45 ppm Calcium, 20 ppm Sodium, 40.8 ppm Magnesium and so forth. With the new numbers I get a missing alkalinity of about 25 ppm as CaCO3, which is fairly low. The residual alkalinity is 8 ppm CaCO3. However, with 20 ppm Calcium and 4.4 ppm magnesium I get a total hardness of 68 ppm as CaCO3. This may have something to do with the way they averaged the results for the report.
Kai
That’s what I was thinking too.
How do you get the missing alkalinity from what was posted though?
You need a water spread sheet that calculates the ion balance. This is the difference between the number of negative (anion) and positive (cation) ions. The ion balance is always 0 but if not all ions are reported or if there are measurement errors the ions may not add up. In my spread sheet I calculate the difference as percentage of the total ion amount. If it’s negative cations are missing and if its positive anions are missing. In this case I entered Ca, Mg, Na, Cl, SO4 and then changed alkalinity (or bicarbonate) until the ion balance was 0.
This doesn’t work when there are other ions that were not reported. But the only ones that could be present in significant amounts is Potassium (K+) which is fairly rare though. Phosphates and Nitrates, which are other cations we don’t usually check for are rare as well. And if they are present in large amounts the water may not be suitable for drinking anyway. This only leaves bicarbonate as ion missing from the list.
In this spreadsheet the ion balance is shown in the upper right corner.
Similar calculations can be done with total hardness. On average 70% of that hardness is calcium and 30% is magnesium. Which leads to a simple formula for RA if only alkalinity and total hardness are available:
RA = Alkalinity - (total hardness / 4)
Kai
OK, that’s what I was thinking - I thought maybe you were using some rule of thumb relating alkalinity and hardness that I didn’t know.
Thank-you Kai for the spreadsheet!! ;D
I will put it to good use…
No magic here. The only rule of thumb that I was able to come up with is the one about residual alkalinity, hardness and alkalinity.
Kai
Bass River as in Yarmouth?
Bass river is a salt water inlet in Beverly Ma
Could the calcium to magnesium ratio be off due to calcium chloride they use on the roads in the winter? The chloride level is high and the report saya it’s due to road deicing as well as other contaminents but that might throw a lot of extra calcium into the water.
Got you, its also a River on Cape Cod
History lesson
General then President Washington wanted to put a canal there in the late 1700’s
Does your report list an average and a range? I’d expect to see fairly large differences due to the seasonality if this were the case.
Some interesting fact to consider since you are talking about rivers: If you know that your water source is surface water then the alkalinity is almost always below 50 ppm. This is because ~50 ppm is the amount of CaCO3 that can stay in solution in water that is at equilibrium with the atmospheric CO2 content. Only when your water comes from a well or has very low calcium content can there be a higher alkalinity.
Kai
No I looked oup the reports back to 2005 and they are within 5ppm of each other
My city water does come from several surface reservoirs and the Ipswich river