Water question - Calcium Carbonate

[FlatFenBrew]

Hi
I have a copy of the Anglian Water report for my area and it gives a Calcium Carbonate figure of 398 and a Calcium figure of 159.2. Am I correct in assuming that to get the Carbonate figure I just deduct one from the other ie 398 minus 159.2 = 238.8?
Reason I ask is that most of the brewing water calculators require a Carbonate number.
Thanks in advance.
Bob

 

[Zephyr259]

They way I understand it is there is a value called "alkalinity" which is generally quoted as ppm calcium carbonate, in my water report it's 35 ppm, you seem to have 398 ppm.

I'm still new to water treatments (but have a read here) but i'm using the Bru'n Water spreadsheet to do my calcs, it converts the alkalinity into a ppm of bicarbonate (42 ppm in my case, estimated 485 ppm for you) which is what you then adjust to get your mash pH in the right region. That's some massively alkaline water you have there, Strange-Steve gives good advice on how to manage it in the thread I linked above. Good luck.

 

[FlatFenBrew]

Thank you very much Zephyr259!

 

[Simonh82]

I've just had a look at an Anglia Water report (just picked a random Peterborough postcode) and it doesn't look like it contains a measure of the water's alkalinity, which is the key to making water adjustments.

The example I found gives the hardness as 262ppm CaCO3 but this isn't the same as the alkalinity. It does give all of the other parameters that you would need for making water adjustments using something like Bru'n'Water, or Brewer's Friend but not the alkalinity.

To test alkalinity get a Salifert test kit which will give you an accurate measure each time you brew, or at least until you've confirmed your water doesn't change seasonally, which some areas do.

With the water report and alkalinity figure you will have everything you need.

One other thing to look out for is that your water company appears to use chloramine to disinfect the water. This isn't removed by boiling, unlike chlorine so you will need to add a campden tablet to avoid potentially unpleasant TCP flavours.

 

[strange-steve]

That's some horrible brewing water you have there, I would definitely be looking for an alternative water source. The alkalinity is manageable but the amount of CRS you'd need would add a ton of sulphate and chloride too. A small portable RO unit off eBay isn't too expensive, and it'll give you a blank slate to build your own water profile.

 

[henteaser]

The example I found gives the hardness as 262ppm CaCO3 but this isn't the same as the alkalinity.

Can you expand on that?

Bru'n'Water uses CaCO3 as the measure of alkalinity.

The Salifert test kit measures carbonate hardness (KH).

These are essentially the same thing. If the water report has CaCO3, why would you require the Salifert kit?

 

[Simonh82]

Can you expand on that?

Bru'n'Water uses CaCO3 as the measure of alkalinity.

The Salifert test kit measures carbonate hardness (KH).

These are essentially the same thing. If the water report has CaCO3, why would you require the Salifert kit?

I will preface this by saying that I am no expert but this is how I understand it from reading up quite a lot on the subject and having my water analysed professionally and with the Salifert kit.

Both hardness and alkalinity can be expressed as ppm CaCO3 but they are not the same thing. Hardness is a measure of how much calcium and magnesium is dissolved in the water. It is commonly expressed as PPM of CaCO3 but you will note that CaCO3 doesn't include Magnesium (Mg) in there, even though magnesium forms part of normal water hardness, CaCO3 is just used as a unit of measurement.

Alkalinity is a measure of the resistance to change in pH of the water. The higher the alkalinity the more acid you have to add to lower the pH. Alkalinity is also often expressed as PPM CaCO3 but hardness and alkalinity can vary.

For instance the alkalinity of my water as measured with a Salifert test kit is usually around 180-190 PPM but the hardness is around 263 PPM CaCO3.

 

[strange-steve]

Can you expand on that?

Bru'n'Water uses CaCO3 as the measure of alkalinity.

The Salifert test kit measures carbonate hardness (KH).

These are essentially the same thing. If the water report has CaCO3, why would you require the Salifert kit?

I will preface this by saying that I am no expert but this is how I understand it from reading up quite a lot on the subject and having my water analysed professionally and with the Salifert kit.

Both hardness and alkalinity can be expressed as ppm CaCO3 but they are not the same thing. Hardness is a measure of how much calcium and magnesium is dissolved in the water. It is commonly expressed as PPM of CaCO3 but you will note that CaCO3 doesn't include Magnesium (Mg) in there, even though magnesium forms part of normal water hardness, CaCO3 is just used as a unit of measurement.

Alkalinity is a measure of the resistance to change in pH of the water. The higher the alkalinity the more acid you have to add to lower the pH. Alkalinity is also often expressed as PPM CaCO3 but hardness and alkalinity can vary.

For instance the alkalinity of my water as measured with a Salifert test kit is usually around 180-190 PPM but the hardness is around 263 PPM CaCO3.

Once again, this is why water treatment is so confusing. Hardness is not the same as carbonate hardness or alkalinity, but carbonate hardness is the same (more or less) as alkalinity. Hardness and alkalinity are both often given as equivalent "ppm as CaCO3", but neither are the same as "CaCO3", ie calcium carbonate. However that being said, tap water below a pH of around 8.3 I believe, doesn't actually contain CaCO3 (the alkalinity will be in the form of bicarbonate) so if your water report has a value for it, it usually means alkalinity as CaCO3 or hardness as CaCO3

This is why I recommend getting a salifert KH kit and measuring the alkalinity for yourself.

 

[FlatFenBrew]

Thanks all.
I bought a Salifert test kit and have a kh value of 14.85 and alkalinity meq/l of 5.3 which if my google found calculation is correct gives 265.25 cac03.

 

[henteaser]

For instance the alkalinity of my water as measured with a Salifert test kit is usually around 180-190 PPM but the hardness is around 263 PPM CaCO3.

Where would you then use that ~180 ppm value in Bru'n'Water?

This field?

 

[FlatFenBrew]

To get my alkalinity value of 265.25 as cac03 I worked this out by multiplying the meq/l of 5.3, (result of Salifert test), by "50"as Jims Beer kit post http://www.jimsbeerkit.co.uk/water_alkalinity.htm
I then used the homebrewforum water treatment calculator, http://www.thehomebrewforum.co.uk/water.php and put the value ( 265.25 ) into the cell as Alkalinity as CaCO3 as it gives the instruction as "enter the value you have measured for Alkalinity "as CaCO3" using the sample kit."
I am pretty sure that I have done it correctly but stand to be corrected from the more experienced brewers.

 

[Simonh82]

Where would you then use that ~180 ppm value in Bru'n'Water?

This field?

Bru'N'Water doesn't actually use the alkalinity figure in the calculations for your mash pH. The spreadsheet uses the alkalinity figure to calculate bicarbonate which, along with the other chemical constituents of the water, the water pH and your grain bill are then used to give guidance when making adjustments.

If you have a figure for alkalinity then there is a section that allows you to convert alkalinity as CaCO3 to bicarbonate. There is also a section that allows you to convert alkalinity as meq/l to bicarbonate. The Salifert kit gives a figure as meq/l so I used this in version of Bru'N'Water.

 

[FlatFenBrew]

Thanks for your help Simon