Salfert Test and Question about Grahams Calculator

[MightyMouth]

Ok, so I got myself a Salfert Kit off of eBay for £5.99 and tested my water.

The results were:
Reading in ml = 0.54
KH value in dKH = 7.0
Alkalinity in meq/L= 2.50 x 50 = 125mg/L CaCO3

If I plug this into the Alkalinity box as CaCO3 in Grahams Calculator it sets the Carbonate level to 74.95 but it doesn't set the Calcium level which I was expecting it to do, am I missing something or is this what I should expect.

My water report shows a Hardness value of 214.7 as CaCO3 which results in a calcium level of 85.97 and a carbonate level of 128.73 if I plug it into the Calculator as Hardness as CaCO3. This time it sets the Calcium level as expected but is significantly different than the value I measured with the kit. Assuming the kit is fairly accurate and that the water report is way out, I can have no confidence in the other values supplied but Severn Trent and so don't have the other values for line 2. The notes say you need at least the calcium, carbonate and sulphate figures and I only have the carbonate.

If I plug my Alkalinity value into the Hardness as CaCO3 box instead, the Carbonate level (74.95) is the same as if I put the value in Alkalinity but it sets the Calcium level to 50.05 which together equal 125ml.

What are my options here? How can I find my Sulphate figures assuming using the values supplied by using the hardness box instead of the Alkalinity box is ok? If I leave the Sulphate level at 0 then the Initial Ion Balance Check is correct so to add anything in the Sulphate box would require something in the Cations side of things to balance it out, presumably Magnesium.

Assuming there is nothing I can do to get enough data to use Grahams Calculator, what can I do to treat my water without the information. I would like to use CRS for Carbonate Reduction for cost and speed.

Can I simply ignore the other values and just reduce alkalinity using CRS and then add some Calcium Sulphate and/or Calcium Chloride and hope the other stuff is ok?

[WallyBrew]

Ok, so I got myself a Salfert Kit off of eBay for £5.99 and tested my water.

The results were:
Reading in ml = 0.54
KH value in dKH = 7.0
Alkalinity in meq/L= 2.50 x 50 = 125mg/L CaCO3

.............. I can have no confidence in the other values supplied but Severn Trent and so don't have the other values for line 2. The notes say you need at least the calcium, carbonate and sulphate figures and I only have the carbonate.

Your previous post "am I doing this right" gave figures from severn trent for sulphate, sodium, chloride and total hardness.

I hope the following makes some sort of sense.

Sodium was given as 20.25 so divide this by 23 (don't ask why) and multiply by 35.5 (don't ask why) you get 31.25 which is not far off 32.3 the figure given for chlorine. So all the sodium combines with the chlorine.

Next - sulphate is given as 75.9 so divide this by 48 (don't ask why) and multiply it by 20 (don't......) and you get 31.6. This is how much calcium is needed to combine with the sulphate.

Next - total hardness is given as 214.7 so divide this by 100 and multiply by 40 (d.........y) and you get 85.9 which is the hardness as calcium.

Next - subtract 31.6 from 85.9 to give 54.3. This is the calcium that is not combined with anything other than, probably the carbonate part. So divide 54.3 by 40 and multiply it by 100 to give 135.8. This is the calculated alkalinity as calcium carbonate and is not far removed from your determined one of 125. This suggests that the figures for sulphate, chloride, sodium and hardness from severn trent are sound.

So follow the instructions in the "brewniversity" for salifert kit and use your determined alkalinity and the calcium (~ 86) and sulphate, chloride and sodium from your water report.

[MightyMouth]

Ok, so I got myself a Salfert Kit off of eBay for £5.99 and tested my water.

The results were:
Reading in ml = 0.54
KH value in dKH = 7.0
Alkalinity in meq/L= 2.50 x 50 = 125mg/L CaCO3

.............. I can have no confidence in the other values supplied but Severn Trent and so don't have the other values for line 2. The notes say you need at least the calcium, carbonate and sulphate figures and I only have the carbonate.

Your previous post "am I doing this right" gave figures from severn trent for sulphate, sodium, chloride and total hardness.

I hope the following makes some sort of sense.

Sodium was given as 20.25 so divide this by 23 (don't ask why) and multiply by 35.5 (don't ask why) you get 31.25 which is not far off 32.3 the figure given for chlorine. So all the sodium combines with the chlorine.

Next - sulphate is given as 75.9 so divide this by 48 (don't ask why) and multiply it by 20 (don't......) and you get 31.6. This is how much calcium is needed to combine with the sulphate.

Next - total hardness is given as 214.7 so divide this by 100 and multiply by 40 (d.........y) and you get 85.9 which is the hardness as calcium.

Next - subtract 31.6 from 85.9 to give 54.3. This is the calcium that is not combined with anything other than, probably the carbonate part. So divide 54.3 by 40 and multiply it by 100 to give 135.8. This is the calculated alkalinity as calcium carbonate and is not far removed from your determined one of 125. This suggests that the figures for sulphate, chloride, sodium and hardness from severn trent are sound.

So follow the instructions in the "brewniversity" for salifert kit and use your determined alkalinity and the calcium (~ 86) and sulphate, chloride and sodium from your water report.

Hey WallyBrew thanks for the great reply, it does make sense. The 135 alkalinity figure is within the margin of error of the Salfert test so that is really close. So what that implies is that relying on just the total hardness as CaCO3 is very inaccurate verging on almost useless and we really must have the actual alkalinity figure. But if it is that easy to determine the alkalinity from the total hardness then why doesn't the calculator do this for us (I realise that the other figures have to be accurate and available) and why are the figures so different if I just use the hardness? I guess it may just be that it would make the calculator unwealdy.

According to the notes if you have both the Hardness figure and the Alkalinity you should put both in so should I put in 125 or 135 as the alkalinity figure? I think in any case my water profile will be greatly improved.

*Edit* Ok so when I put all the figures in everything balances pretty well but there is no Magnesium. I think I read somewhere that magnesium is important for the fermentation but that there is Mg in the grain so no need to add. Any thoughts on this as if I could get away without adding Mg then I wouldn't have to buy Epsom Salts or Calcium Chloride and could get away with just Gypsum but if I need to add MG then I also have to add Calcium Chloride. Most of the target profiles call for a little Mg so if it is important then I will buy some.

[Aleman]

I normally add enough magnesium sulphate to add an additional 5ppm magnesium . . . somewhere around 0.2g in 25L!!

[MightyMouth]

Thanks Aleman, I will get some as it's not like they are expensive.

[gregorach]

I got a kilo of Magnesium Sulphate BP off eBay for a couple of quid. Should last me into the next millennium.

[Steve1262]

I'm starting to loose the will to live. It's no wonder water treatment is such a formidable subject.

[fisherman]

For making light or bitter beers you should need to add 0.5 ml CRS per litre for all liquor and .85 grms per litre DLS for the 25 litres only to have a good balanced liquor. I hope I'm right?