Struggling with Bru'n Water spreadsheet

[JRTurner1234]

Hi,

I'm struggling with the inputs on the Bru'n Water spreadsheet. I recently commissioned a water analysis for my local water supply, but when I input the data from the lab into the Bru'n Water spreadsheet I get an error message telling me that the 'Water is Unbalanced'.

Here are the inputs I'm using:

pH 7.13
Nitrate 29.3
Total Hardness (as CaCO3) 308
Calcium 61.47
Magnesium 2.88
Chloride 27.63
Sulphate 23.45
Alkalinity (as CaCO3) 280
Nitrate 29.3
Sodium 16.8 (from separate waterboard report)
I've been told by the lab to input Carbonate as 0
I've been told by the lab to input Alkalinity as HCO3 as 341.6 (calculated by 280 * 1.22)


I've attached the report from the lab for you to review.

What's going wrong here?! Any help much appreciated!!

Thanks,
Jamie

 

[MyQul]

Sorry I can't help you myself but forumite @mabrungard is the guy that actually invented bru n water. I'm not sure how often he stop by (last visit 16th May '16) but if noone else can help he'll get a notification and see this and hopefully help you out

 

[serum]

I had exactly the same problem with a Thames water one but I've no idea how to sort it. The one for the bottled water I use seems to work fine though.

 

[Simonh82]

Martin Brungard is probably easier to find on the Homebrewtalk forum. Check the brewing science sub forum. He has answered questions for me there before.

Bru n' water uses the carbonate figure for calculating the residual alkalinity which is the basis of the suggested water adjustments. The alkalinity figure is used by the spreadsheet to work out the bicarbonate/carbonate level which is the used in the water adjustments sheet.

I would enter the figure that Bru N' Water tells you for bicarbonate based on your alkalinity.

 

[mabrungard]

I'm assuming this was a Murphy's water test? As most know, they don't provide a sodium content for the water and that actual level in the water could be high or negligible. You just don't know.

In the case of most potable water supplies, the primary ions in our water are: Ca, Mg, Na, SO4, Cl, and some sort of carbonate species (typically HCO3). Any other ions in drinking water are typically at trace levels (less than a few ppm). With this reality, we can make an educated guess about the sodium content in water by assuming that the missing sodium content is what is producing the ion imbalance. This assumes that the cation total is less than the anion total. Adding sodium content to bring that cation total to equal the anion total is a reasonable option. All water is always ionically balanced, its just that our testing or the results may not be complete enough.

So try adding sodium content to the water report inputs to the point that the report is balanced. In the case of the newest free version of Bru'n Water, you will need to bracket the upper and lower sodium content where the Imbalance warning is shown and then assume the true sodium content that you should use is the average of that upper and lower values.