Help needed inputting Murphy's water report into Bru'n Water

[inthedark]

I've been searching the boards to see if anyone has asked this before but got nowhere.

My local water company's report dates back to 2012 and omits most useful information for brewing so I've got myself a report from Murphy's. Problem is, that doesn't provide info I can directly type into any of the models I've found. I'm focussing on trying to use Bru'n Water but I've also tried and failed to use Graham Wheeler's calculator.

My figures are:
pH 7.16
Nitrate 30
Calcium 115
Magnesium 3
Chloride 24.58
Sulphate 15.79
Alkalinity (as CaCO3) 329

I've had to use the TW2012 figures for Na (13.3) and Fe (1.3) and have nothing for K.

I'm really confused about the bicarbonate / carbonate part. If I put my alkalinity figure into the 'Total Alkalinity' box to calculate the split, it gives me 400.9ppm Bicarbonate and 0.2ppm carbonate - if I put those in the boxes the ion balance is out by 1.48. Have I done the right thing here? If so, where am I likely to find the discrepancy?

Hope someone can help, if I can get this to balance I can try to move forward with the rest of the tool!

Thanks

Paul

[WallyBrew]

1. Enter 16 for the sodium to balance the chloride

Next - that alkalinity if it is as CaCO3 is way off, it is more likely to be as HCO3

This should now balance as in within 0.5meq

you should have
cations 6.68meq
anions 6.83meq


when you go to the water adjustment page you will see

cations 6.7meq
anions 6.4meq

this is because it has thrown your nitrate to the wind and unbalanced your water.

It does the same thing with potassium - you can enter 4000 in there and it's thrown away

perhaps Mr. Brungard would like to explain why this is done?

[inthedark]

Next - that alkalinity if it is as CaCO3 is way off, it is more likely to be as HCO3

OK, so I put my 329 figure into the Bicarbonate box, right?

If I do that the calculated 'Alkalinity (ppm as CaCO3)' comes out as 272 which is closer to my own Salifert test which came out as 246, but that's a pretty big mistake for a professional lab to make isn't it? Is this common?

[WallyBrew]

f I do that the calculated 'Alkalinity (ppm as CaCO3)' comes out as 272 which is closer to my own Salifert test which came out as 246, but that's a pretty big mistake for a professional lab to make isn't it? Is this common?

No comment on at least one of the words in your reply or the question

[mabrungard]

Its a bit of a jump to assume that the sodium content is only paired with the chloride. I'm not sure that 16 ppm is the right value.

This does seem to be a significantly unbalanced water report. The anion total is rather high. The fact that the lab result is substantially different from the field test is troubling. Does the source water quality vary greatly?

Wally, I am unclear by what you mean regarding the nitrate and potassium. If they are detected at significant quantity in the water testing, they need to be part of the ionic balance. Are you saying that the nitrate value shouldn't be included when totaling the cations and anions?

[inthedark]

Does the source water quality vary greatly?

I don't know, I've only done two tests about a week apart, so that's probably not enough to go on. Interestingly, when I plug the numbers I have into GWs calculator but change the alkalinity as suggested, it balances closely, with no need to change the sodium number. I just don't yet understand why that model shows carbonates but no bicarbonates when the other one states that with the pH of my water the carbonates should be effectively zero.

[Eric]

If I do that the calculated 'Alkalinity (ppm as CaCO3)' comes out as 272 which is closer to my own Salifert test which came out as 246, but that's a pretty big mistake for a professional lab to make isn't it? Is this common?

Got mine from Murphy's too, 312mg/l CaCO3 according to them when it's 240 according to a Salifert kit. (Similar proportional error to yours.)
Next I used Murphy's sulphuric acid to reduce alkalinity to 40, which took 0.432ml/l, but according to Murphy's data for their acid, that quantity would have reduced alkalinity to 185mg/l CaCO3, assuming it was 312 at the start.

There's a moral somewhere.

[inthedark]

Interesting, did you ask them about the discrepancy? Maybe I should ask them what they think.

[WallyBrew]

Wally, I am unclear by what you mean regarding the nitrate and potassium. If they are detected at significant quantity in the water testing, they need to be part of the ionic balance. Are you saying that the nitrate value shouldn't be included when totaling the cations and anions?

No.

I'm questioning why your water adjustment page disregards them?

By doing this the users water is always going to be out of balance whilst the given profiles are in balance as they are balanced against Na, Mg, Ca, SO4, Cl and alkalinity.

[Eric]

Interesting, did you ask them about the discrepancy? Maybe I should ask them what they think.

Not yet, the data was only received yesterday. I need to get my head around it to see where they went wrong this time. I'm wondering if they've confused total hardness as mg/l CaCO3 with alkalinity in those units?
They've yet to fully answer my last query and continue to publish incorrect data on their website. I'm told they're very busy.

[inthedark]

OK, I've written to the lab manager to raise my concerns, and linked back to this thread for reference. I'll update here if I hear anything.

[Dave S]

If I do that the calculated 'Alkalinity (ppm as CaCO3)' comes out as 272 which is closer to my own Salifert test which came out as 246, but that's a pretty big mistake for a professional lab to make isn't it? Is this common?

Got mine from Murphy's too, 312mg/l CaCO3 according to them when it's 240 according to a Salifert kit. (Similar proportional error to yours.)
Next I used Murphy's sulphuric acid to reduce alkalinity to 40, which took 0.432ml/l, but according to Murphy's data for their acid, that quantity would have reduced alkalinity to 185mg/l CaCO3, assuming it was 312 at the start.

There's a moral somewhere.

I had a similar discrepancy with my report from Murphy's but in the other direction. They reckoned 165 alkalinity, but whenever I measure it using Salifert I get 190-195. So I don't know what's going on there. What I do know is that when I reduce the alkalinity with phosphoric acid using Bru'nW, using a starting point of 190 and re-measure, It comes out very close to the predicted value.

[Eric]

If I do that the calculated 'Alkalinity (ppm as CaCO3)' comes out as 272 which is closer to my own Salifert test which came out as 246, but that's a pretty big mistake for a professional lab to make isn't it? Is this common?

Got mine from Murphy's too, 312mg/l CaCO3 according to them when it's 240 according to a Salifert kit. (Similar proportional error to yours.)
Next I used Murphy's sulphuric acid to reduce alkalinity to 40, which took 0.432ml/l, but according to Murphy's data for their acid, that quantity would have reduced alkalinity to 185mg/l CaCO3, assuming it was 312 at the start.

There's a moral somewhere.

I had a similar discrepancy with my report from Murphy's but in the other direction. They reckoned 165 alkalinity, but whenever I measure it using Salifert I get 190-195. So I don't know what's going on there. What I do know is that when I reduce the alkalinity with phosphoric acid using Bru'nW, using a starting point of 190 and re-measure, It comes out very close to the predicted value.

Yes, CRS, 85% phosphoric acid and 36% hydrochloric acid also confirm my Salifert findings of 240mg/l CaCO3.
Only the test using Murphy's sulphuric acid and their data didn't confirm my other tests. That made the alkalinity to be 159mg/l CaCO3, another vast discrepancy, this time in the opposite direction.

[Dave S]

They seem to be heading for a vote of no confidence.

[Aleman]

They seem to be heading for a vote of no confidence.

Which considering that the tests are done with an automated device . . . is . . . . concerning