Advice needed on my local tap water

Water analysis, treatment, and mineral recipes for optimum taste and equipment health.
czegledi

#1: Post by czegledi »

I am getting more serious about espresso and I would like to know how my (tap) water is and if there is something I should do about it to improve my extractions while protecting the espresso machine.

Extracted from my municipality's (Gothenburg, Sweden) water report, the tap water I'm using should be:
Total harddess: 23 mg/l
Calcium (ICP-MS): 21 mg/l
Magnesium (ICP-MS): 1.5 mg/l
Alkalinity: 1.01 mmol/l
pH at 25 C: 7.9

I don't know what ICP-MS stands for.

The full report can be found, in Swedish though, here https://goteborg.se/wps/wcm/connect/efd ... OD=AJPERES, "Alelyckan dricksvatten" column.

From my very basic understanding, the water seems very soft and it may be too soft. I cannot judge whether it's corrosive or not.

What do you think about the water and what do you recommend me to do about it to improve my extractions? Unfortunately, I cannot plum in my espresso machine in my current kitchen.

I see the BWT pitcher is popular. Do you think it fits my need?

Any suggestion is much appreciated!
Cristian

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homeburrero
Team HB

#2: Post by homeburrero »

czegledi wrote:I don't know what ICP-MS stands for.
https://en.wikipedia.org/wiki/Inductive ... ectrometry

Your calculated total hardness in that report is odd -- not clear how they are quantifying it. But you can easily calculate it in conventional CaCO3 equivalence units yourself from your calcium and magnesium ion numbers:

Calcium hardness (median) = 21 * 2.5 = 52.5 mg/L CaCO3 equivalent
Magnesium hardness (median) = 1.5 * 4.12 = 6.18 mg/L CaCO3 equivalent
so the calculated total hardness in conventional units of CaCO3 equivalent is 58.7 mg/L

Your alkalinity of 1.0 mmol/L converts to 50 mg/L CaCO3 equivalent


Pretty nice water you have there. Even at the upper end of the range in that report it will deposit little if any scale.

Another nice thing about that water is your chloride (klorid) level. At your 8 - 12 mg/L it should not be a problem. (High levels of chloride can be a corrosion concern, and chloride ion not easily removed without resorting to reverse osmosis systems.)

All you really need is a filter that removes particulates, chlorine (klor), off-tastes and odors. A charcoal pitcher filter will do that nicely. I like the Brita Longlast for that because it's a pure charcoal filter and contains no softening/acidifying resins -- but not sure you can get it there. I think the BWT pitcher filter would work OK.
Pat
nínádiishʼnahgo gohwééh náshdlį́į́h

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xlabor

#3: Post by xlabor »

Could you help me too? Is it safety or should I use alternative method?
I have a month a Dalla Corte Studio 2021 and I use it with BWT Mg2+ filter jug with my tap water what is:
Klorid: 4 mg/l
pH: 7,24
Alkality: 7,1 mmol/l
194 mg/l CaO
20 nk

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homeburrero
Team HB

#4: Post by homeburrero » replying to xlabor »

That water has nice low chloride, but is much too hard and scale prone for use in an espresso machine and the BWT pitcher filter will not reliably soften it. Your best bet for now is to switch to a softer bottled water. I think you can get Volvic there, and that would work. You don't want to use purified (RO, distilled, deionized) unless you add some mineral to it.

Converting those numbers to conventional CaCO3 equivalents, your tap water has a bicarbonate alkalinity of 355 mg/L and a hardness of 346 mg/L.

P.S. [edit addition] maybe a good idea to show how i converted . . .
molar mass of CaCO3 = 100 mg/mmol
molar mass of CaO = 56.1 mg/mmol

At a pH of 7.2 you can assume that all alkalinity is due to bicarbonate ion, which is univalent, so 7.1 mmol/L is chemically equivalent to 3.55 mmol/L of divalent CaCO3. 3.55 mmol/L * 100 mg/mmol = 355 mg/L CaCO3

194 mg/L / 56.1 mg/mmol = 3.46 mmol/L CaO
3.46 mmol/L * 100 mg/mmol = 346 mg/L CaCO3
Pat
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xlabor

#5: Post by xlabor »

Thank your answer.
Is this bottled water is good? Or should I filter it more?
Ca2+63 mg/l;
Na+21 mg/l;
Mg2+26 mg/l;
HCO3 400 mg/l.
Total content: 520 mg/l.

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homeburrero
Team HB

#6: Post by homeburrero »

xlabor wrote:Is this bottled water is good? Or should I filter it more?
Ca2+63 mg/l;
Na+21 mg/l;
Mg2+26 mg/l;
HCO3 400 mg/l.
Total content: 520 mg/l.
No, that water is still too hard. You need to find a bottled water on the soft side. In terms of Ca2+ ion you are shooting for values below 20 mg/L.
Pat
nínádiishʼnahgo gohwééh náshdlį́į́h

xlabor

#7: Post by xlabor »

Thank you!

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xlabor

#8: Post by xlabor »

I only found bottled water with about 30 mg/l Ca content or much higher.
This is:
- potassium 3,0
- sodium 141,1
- calcium 32,2
- magnesium 14,5
- nitrit <0,02
- cholird 6,2
- HCO 543,0

Total: 761 mg/l.
pH 6,86

is it good or should I filter it with ion exchanger too? Can I use tap water with Oscar or that is too hard for the machine?

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homeburrero
Team HB

#9: Post by homeburrero »

xlabor wrote:I only found bottled water with about 30 mg/l Ca content or much higher.
This is:
- potassium 3,0
- sodium 141,1
- calcium 32,2
- magnesium 14,5
- nitrit <0,02
- cholird 6,2
- HCO 543,0

Total: 761 mg/l.
pH 6,86
That's better on the calcium level, is almost as low as Acqua Panna, which some people use. But still has that high alkalinity and so probably will be fairly scale prone. Converting the numbers:

Calcium: 32.2 mg/L (as ion), 85.5 mg/L as CaCO3
Magnesium: 14.5 mg/L as ion, 59.7 mg/L as CaCO3
Total hardness: 85.5 + 59.7 = 145 mg/L as CaCO3 = 14.5 French degrees
Bicarbonate alkalinity: 543 mg/L as HCO3 ion = 445 mg/L as CaCO3 (that's really high!)

You might try searching specifically for water that is marketed as coffee maker water.



Another solution that may well be your most economical option would be to buy distilled (or otherwise purified) and mix in some of your hard tapwater. If you added 120 ml of tap water to 1 liter of distilled you would end up at about 37 mg/L calcium hardness (as CaCO3) and about 40 mg/L alkalinity (as CaCO3). Ideal alkalinity, some calcium hardness, and would give you little or no limescale, and plenty of mineral for the water level sensors to work properly.
Pat
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czegledi (original poster)

#10: Post by czegledi (original poster) »

homeburrero wrote: All you really need is a filter that removes particulates, chlorine (klor), off-tastes and odors. A charcoal pitcher filter will do that nicely. I like the Brita Longlast for that because it's a pure charcoal filter and contains no softening/acidifying resins -- but not sure you can get it there. I think the BWT pitcher filter would work OK.
@homeburrero Many thanks for your detailed answer!

Unfortunately Brita does not sell the Longlast filter over here. They sell the Maxtra+ filters, which seem not to be only a charcoal filter and reduce hardness as well. If I go with the BWT Penguin pitcher, should I be worried that the water may become too corrosive?