Water filter to protect my espresso machine

Water analysis, treatment, and mineral recipes for optimum taste and equipment health.
4go

#1: Post by 4go »

Hello All!

I'm looking for the best way to protect my profitec pro machine with stainless steel boilers.
With my old machine i used so called "design water" which was made from RO water + Epsom salt + baking soda. Then i was afraid of corrosion due to lower PH level (~6.x). My "new" machine arrived then i swapped to rpavlis water: RO water + potassium bicarbonate (1l/0.1g). Now, im looking for the best way to protect the machine, so im reading about water filters. In our country BWT is the most known, especially BWT BestProtect.
Im afraid that if something is going wrong with the potassium bicarbonate RO water, i can damage my machine.
But, as i read and read of our local forums, they said, maybe BWT BestProtect is not the best choice because of the chloride level of the water.

Here is our tapwater's data:
-ammonium ion: <0.02mg/L
-calcium 79mg/L
-potassium 1mg/L
-chloride 9mg/L
-magnesium 48.5 mg/L
-manganese <0.02mg/L
-m-alkalinity 7 mmol/L
-sodium 5mg/L
-nitrate 20mg/L
-nitrIte <0.01mg/L
-total hardness 22 nk
-ph 7.51
-sulfate 10mg/L
-iron 0.04mg/L
Im totally confused. My goal is to protect the machine even if i have to sacrifice some taste of my coffe...
What is your advice? Where to go? BWT? RPavlis water? What is the most safe/trouble-free choice?

Thanks in advance!

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homeburrero
Team HB

#2: Post by homeburrero »

That's really hard water! Fortunately has nice low chloride given the high hardness.

Translating to conventional units . . .
calcium hardness = 198 mg/L CaCO3 equivalent
total hardness = 393 mg/L CaCO3 equivalent
alkalinity = 350 mg/L CaCO3 equivalent
chloride ion = 9 mg/L

The chloride here is not an issue, but since it's so very hard I think it best to avoid a decarbonizing softener because of their acidifying effect given such high hardness*. A conventional softener like the BWT Bestprotect would be better than a decarbonizer like the BWT Bestmax. With a conventional softener here you would end up with really high alkalinity, which may dull the taste. You would need fairly frequent replacement or recharge of the softener - - a 1000 grain softener cartridge would be depleted in about 40 gallons of use.

If you can get purified water I think your most trouble free solution would be to make rpavlis water. Or you could dilute your tapwater maybe 6 parts distilled to 1 part tapwater. For plumbed-in your best bet would be a high end RO system with a blending valve. Be aware that many RO systems don't handle water this hard without a softener in front of the system.



* SCA Water Quality Handbook , section 9.2:
"The working principle of the decarbonizer that reduces total hardness and alkalinity is based on the exchange of magnesium or calcium ions by protons. This means that although the hydrogen carbonate is protonated and therefore not an acid buffer anymore, it is still present in the form of carbonic acid, which in turn is in a constant exchange with dissolved carbon dioxide. If the treatment is done by an in-line system where the carbonic acid cannot escape as carbon dioxide, it leads to two effects. Firstly, the pH of the treated water will decrease and in case of a water with a high starting level of total hardness (i.e. > 300 ppm CaCO3), this can effectively make the treated water so acidic that the risk of corrosion increases significantly. Secondly, a large amount of carbonic acid will also lead to excessive crema production during the extraction of espresso."


P.S.
I was befuddled by the "total hardness 22 nk" and learned something new. Googling taught me that nk ° is sometimes used to describe German degrees of hardness.
Pat
nínádiishʼnahgo gohwééh náshdlį́į́h

4go (original poster)

#3: Post by 4go (original poster) »

Thank you for your answer!
So your opinion to instead of bwt bestprotect, use rpavlis water made from RO water like i do it now?

Ps. Yes, my bad, 22nk means German hardness in this water report.

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homeburrero
Team HB

#4: Post by homeburrero »

4go wrote:So your opinion to instead of bwt bestprotect, use rpavlis water made from RO water like i do it now?
I would go with the rpavlis because it's easy, and reliably scale-free and machine safe.

The bestprotect should also be fine if you find that more convenient. It would give you water with all that 350 mg/L alkalinity which is much more than most people recommend for coffee taste reasons, due to dulling the brew's acidiy. Espresso tolerates much higher alkalinity than regular brewed coffee so maybe not a big issue. You'd want to keep an eye out for scale. The filter cost would not be a major issue - - based on your 22 °dGH hardness, a size V filter should handle about 650 liters before the resin is exhausted (per http://voltagephotos.com/manuals/BWT/BestProtect.pdf ).
Pat
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4go (original poster)

#5: Post by 4go (original poster) replying to homeburrero »

Thank you for your reply!

In my case, BWT filter costs about ~200usd, while Rpavlis water almost 0. (RO filter i already have, potassium bicarbonate was about 7usd for a lifetime (500g).) In this case, what you recommend? I dont want to spend 200usd "at all cost", only if you say it protects my machine better.

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homeburrero
Team HB

#6: Post by homeburrero »

4go wrote:n my case, BWT filter costs about ~200usd, while Rpavlis water almost 0. (RO filter i already have, potassium bicarbonate was about 7usd for a lifetime (500g).) In this case, what you recommend? I dont want to spend 200usd "at all cost", only if you say it protects my machine better.
I'd say stick with the rpavlis in your case - it's simple, inexpensive, and reliably protects the machine.
Pat
nínádiishʼnahgo gohwééh náshdlį́į́h

4go (original poster)

#7: Post by 4go (original poster) »

Thank you very much! You helped me a lot! I will stick to it!

Just to be sure: RO water with minerals based on Rpavlis method means 1l RO water with 100mg potassium bicarbonate, right? (1gal (~3.8L with 400mg was the base recipe i have found reading forums)

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homeburrero
Team HB

#8: Post by homeburrero »

Just to be sure: RO water with minerals based on Rpavlis method means 1l RO water with 100mg potassium bicarbonate, right? (1gal (~3.8L with 400mg was the base recipe i have found reading forums)
Yes - The full strength recipe is 100 mg of potassium bicarbonate per liter, which for a US gallon would be 0.38 gram. No need to be precise, appx 0.4 gram per gallon is close enough. Dr Pavlis said that for dark roasts he might use as little as half that amount for taste reasons. The full strength gives you an alkalinity of 50 mg/L in CaCO3 equivalents and have a conductivity of around 120 µS/cm at 25℃, which would read around 60 ppm on an inexpensive TDS meter.
Pat
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