What water filtration to use?

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

#1: Post by pocmaraty »

Hello,

at first, sorry for my english. Recently i bought a new machine, Rocket Giotto Type V. And we have here hard water. I can see it on kettle, scale build up realy quickly. So I was looking for some water filtration. What i have found is BWT Bestmax Premium. But i am not sure if it's the right solution for me.
On webpage of my local water supplier i found this :

calcium : 103,35 mg/l
magnesium : 27.4 mg/l
pH : 7.41
chlorid : 14.8 mg/l
chlorine : 0.25 mg/l
hardness : 3.71 mmol/l or 20.8°N
conductivity : 79.23 mS/m
sulphates : 41,55 mg/l

Can i use this kind of filtration on my water or do i need something else, Like RO, to protect my new machine from scale and corrosion.
Thanks for help.

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BladeAndStone

#2: Post by BladeAndStone »

You could contact Rocket directly since they will be familiar with metric measurements and can advise for the machine.

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homeburrero
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#3: Post by homeburrero »

pocmaraty wrote:Can i use this kind of filtration on my water or do i need something else, Like RO, to protect my new machine from scale and corrosion.
You are missing a key number -- the alkalinity, or what the Bestmax people refer to as carbonate hardness. What you have for 'hardness' is clearly the general hardness, and it is very high. (3.71 mmol/L general hardness is equivalent to 371 mg/L as CaCO3, or 20.8°German degrees)

Most likely this water also has a high alkalinity up in the 200 - 350 mg/L as CaCO3 (which would be 11 - 20 °dKH) and would require a low bypass setting on the Bestmax head.

There is a downside to that filter in that it will acidify your water when run with low bypass and a high alkalinity.* That's a very serious downside when you have significant chloride, but your chloride at about 15 mg/L is not that bad.

If you had a Synesso machine, they would certainly advise you not to use the BWT Bestmax (or any decarbonizing filter) with this water. (They are fairly conservative about chloride and corrosion risk.)

If you want to be very cautious, you would choose RO with this water, and remineralize either with a bypass valve (some high-end RO systems have that feature) or a simple remineralization cartridge.

* Section 9.2 of the SCA Water Quality Handbook has a good discussion and chart about this, with a caveat that using decarbonization to treat a water with a hardness of >300 mg/L as CaCO3 can make it so acidic that the risk of corrosion increases significantly.
Pat
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slybarman

#4: Post by slybarman »

I hope the OP won't mind if I piggy-back on his thread. I was also considering the BWT Bestmax premium. My water conditions are:

Hardness: 40-55 mg/L or 2-3 grains per gallon (my own testing with strips gave 25 mg/L but that was after running through the refrigerator EveryDrop filter)
Alkalinity: 30-40 mg/L calcium carbonate
Chlorides: 4 ppm or 4 mg/L sodium
PH: 7.5-8

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homeburrero
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#5: Post by homeburrero »

slybarman wrote:Hardness: 40-55 mg/L or 2-3 grains per gallon (my own testing with strips gave 25 mg/L but that was after running through the refrigerator EveryDrop filter)
Alkalinity: 30-40 mg/L calcium carbonate
Chlorides: 4 ppm or 4 mg/L sodium
PH: 7.5-8
I think the BWT Bestmax would be a waste of money with this ^^^^ water. The Bestmax is a decarbonizing (aka WAC resin) filter that tends to reduce both the alkalinity and the hardness, and needs more alkalinity than that to perform well for espresso machine water.

Your alkalinity (what BWT refers to as carbonate hardness) is already as low as it needs to be, and your alkalinity and hardness considered together are not high enough to cause scale problems. What you need is a simple activated charcoal or carbon block + particulates filter.

P.S.
If you wanted to fully guarantee that you would never need to descale even in a hot steam boiler, then you could consider adding a conventional cation exchange system in line with the carbon filter. These are very inexpensive, and some of them can be recharged with salts. That type of softener removes calcium and magnesium (replacing it with either sodium or potassium) , keeps your 30-40 mg/L alkalinity up where you want it, and does not lower the pH.
Pat
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slybarman

#6: Post by slybarman » replying to homeburrero »

Thank you. Any particular brand or model you recommend? My primary concern is scale. The flavor I get from the tap water is just fine.

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homeburrero
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#7: Post by homeburrero »

slybarman wrote:Any particular brand or model you recommend?
There are lots that would be fine, but one that I'll mention because it's from a reputable espresso machine vendor (and HB sponsor) who clearly documents the whole system would be this one from CCS.

The filter replacement cost on one like that would be very low, well under $100 per year if you replace both filters every 6 months. For your softish water, the capacity of that softening cartridge is more than you'd deplete in a year, but replacement at 6 months max is usually recommended for these filters.

This setup with your (slybarman's) water would give you near zero hardness, 30 - 40 mg/L alkalinity, non-scaling water similar to the the R Pavlis recipe (distilled + bicarbonate) water that a lot of people on this forum use and like. However, many people would argue that you would get better taste if you did not soften your water, which is low enough in hardness that you would need to descale infrequently if ever. To go that route you could use the version of that filter system that only has the charcoal block filter.

P.S.
Another example one that would do the job in one cartridge would be the Cuno/3M PS124 cartridge system sold by Stefano's Espressocare (another reputable vendor and HB sponsor).
Pat
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slybarman

#8: Post by slybarman » replying to homeburrero »

Thank you. I will give those a look. In the past I tried several of the ion exchange softeners and did notice a degradation in flavor, so if I can get away without one I'm inclined to do that. The carbon block should be pretty similar to what I get off the refrigerator today.

Cerberus

#9: Post by Cerberus »

@homeburrero - any chance you can please help me out with filtration as well?

I'm currently using the softener from Lelit, but I'm looking to plumb my machine and have been spending waaaaayy too much time looking into filters, yet I still can't seem to figure out what I need (if anything). Based on my city's water report (2018 data) these are the figures:
  • Chloride: 19.6
  • TDS: 160
  • Magnesium: 7
  • Calcium: 33
  • pH: 7-7.7 (avg 7.3)
  • Alkalinity: 80.5
  • Hardness (as CACO3): 117 (per test strip, it's 120, so 117 seems accurate)
I don't think I need BWT and, based on my understanding and using Langelier Index calculator, I would have minor scaling and would be fine with either 3M/Cuno, generic Pentek from CCS or Homeland filter from Clive.

Thoughts?

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homeburrero
Team HB

#10: Post by homeburrero »

If it were not for that chloride, a decarbonizing filter like the BWT bestmax might work well for that water -- it could drop the hardness and the alkalinity together down to reasonable numbers.

But I think I'd stick to a conventional softener like the ones you mentioned to avoid acidifying the water an dropping the alkalinity. You don't want that when you have borderline chloride. By dropping the hardness very low you can live with that 80 mg/L alkalinity and not worry about limescale. And especially in espresso, 80 mg/L alkalinity would not be so high as to affect taste. (Compared to brewed coffee, an espresso has less brew water and can tolerate far more alkalinity in that water. )

A very cautious person might even go to an RO system for this water to get rid of that chloride. (Synesso, for example, recommends RO whenever the chloride is above 15 mg/L.)
Pat
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