Hello,

Finally got a box of different fancy aquarium drop tests.
This is what I have:

• GH: 6 dH

• KH: 7 dH

• pH: 8.0-8.2

• Na+: 14 mg/L (February measurement - awaiting new data) - may explain

So, total hardness is within fancy recommendations, but bicarbonates are all over the place.
There are many softening and mineralising devices, but not so many dealkalisers.
Obviously, RO will bring order - but I would love to avoid that. Expensive, huge, cumbersome.

Does anyone have any experience or ideas on what can be done?

Take all recommendations with a grain of salt, but it's true that your GH numbers and KH numbers, taken together, are on the high side and would be scale prone.

old_bear wrote:There are many softening and mineralising devices, but not so many dealkalisers.

There are no filters that specifically raise or lower just the alkalinity, but there are lots of decarbonizing filters on the market that lower both hardness and alkalinity by a roughly equal amount. These are also referred to as WAC resin softeners, or as hydrogen ion exchange softeners. Some of the popular ones include the Pentair/Everpure Claris, the Brita/Mavia Quell ST, and the BWT Bestmax. Most of these have an adjustable bypass filter head and claim to reduce "carbonate hardness" in the product lit.

They differ from old fashioned conventional softeners in that they use a weak acid cation (WAC) exchange resin that does not exchange sodium or potassium for hardness cations, but rather exchanges hydrogen (H+) ions. The released H+ ions then react with the bicarbonate buffer, so you end up with lower alkalinity, lower hardness, and lower pH, all three of which act to reduce the limescale risk. This resin cannot be recharged with salt. You must simply replace them when they are exhausted, which you can estimate based on the carbonate hardness (KH), bypass setting, and water throughput.

That is what I am thinking about: decarboniser (BWT Bestmax premium?) with evil bypass setting or desalinator (BWT Bestclear?) and following remineraliser (BWT bestmin).
Clumsy, but still much lighter and cheaper than RO. It is very difficult to understand if the numbers will do.

But what concerns me is the amount of written information about softening, and very little about "moving to the left" specifically.

old_bear wrote:That is what I am thinking about: decarboniser (BWT Bestmax premium?) with evil bypass setting

I think that would be my choice, probably the simple Bestmax dialed to where the alkalinity drops down to the 3 °dHK neighborhood. That's assuming the water doesn't have troublesome high chloride ion.

old_bear wrote:or desalinator (BWT Bestclear?) and following remineraliser (BWT bestmin).
Clumsy, but still much lighter and cheaper than RO. It is very difficult to understand if the numbers will do.

That's getting into expensive and uncharted territory. And as you say, those filters are very poorly specified. The Bestclear Extra has some sort of mixed bed cation and anion exchange resin and with zero bypass may come out with very low TDS. But it may also produce water with a neutral or higher pH which would make using a remineralizer cartridge ineffective. It appears that BWT does not market it as a solution for espresso machines.

Pentair sells a mixed bed demineralizing filter called the Claris Prime, which has had some discussion on HB as a possible alternative to RO. But it is also expensive and I've seen no positive feedback so far on it being a viable solution for a home espresso machine.

homeburrero wrote:I think that would be my choice, probably the simple Bestmax dialed to where the alkalinity drops down to the 3 °dHK neighborhood. That's assuming the water doesn't have troublesome high chloride ion.

Well. There is some sodium. If it did not come alone (marine clay or whatnot), there may be some cloride.
Problem is, I am not sure how decarboniser would do in the absence of cations. E.g. when all the calcium is gone, but there is still a lot of bicarbonates, what happens?

homeburrero wrote: That's getting into expensive and uncharted territory. And as you say, those filters are very poorly specified.

Fishy strange RO costs here around 7-8 thousand money. More or less sensible begins at 20.
All these smart bottles are around 2-5 for the whole setup. So RO stands as way more expensive still - not counting the mess with much more space to use. Especially given my dream of two independent points of use.

homeburrero wrote:The Bestclear Extra has some sort of mixed bed cation and anion exchange resin and with zero bypass may come out with very low TDS. But it may also produce water with a neutral or higher pH which would make using a remineralizer cartridge ineffective. It appears that BWT does not market it as a solution for espresso machines.

We don't really know what BWT really markets for. They promote some of the things, but I'd say it seems deliberately discreet: "reach us, we will say what's best for you". I hate it so much. It is so very bad. If there'd be any other vendor reachable...
And they have RO systems for the purpose, which explains why desalinator is just not that interesting.
Problem is, that means that a country office has to give clever advisory. And if it does not, good luck guessing.

homeburrero wrote:Pentair sells a mixed bed demineralizing filter called the Claris Prime, which has had some discussion on HB as a possible alternative to RO. But it is also expensive and I've seen no positive feedback so far on it being a viable solution for a home espresso machine.

Interesting, but the paper emphasises anions only?
Besides, I am unsure Pentair is that easy to acquire here (possibly, doable).

old_bear wrote:

Fishy strange RO costs here around 7-8 thousand money. More or less sensible begins at 20.
All these smart bottles are around 2-5 for the whole setup.
L

But most of the bottle setup cost is the cartridges, not the heads, and they have to be replaced every 6 to 12 months, that's not at all cheap over a few years if you run some supercharged setup with 2+ cartridges. Just my 2c.

old_bear wrote:Well. There is some sodium. If it did not come alone (marine clay or whatnot), there may be some cloride.
Problem is, I am not sure how decarboniser would do in the absence of cations. E.g. when all the calcium is gone, but there is still a lot of bicarbonates, what happens?

Your 14 mg/L sodium would only be about 21 mg/L chloride if it were all NaCl, so your chloride is probably not problematic. And WAC resin decarbonizer does no carbonate reduction if if the water has no divalent cation (calcium and magnesium) - basically does nothing in that case.

old_bear wrote:Interesting, but the paper emphasises anions only?

The Pentair Claris Prime literature is also lacking in detail. Of course it must remove an equivalent net charge of cations and anions. Interestingly it appears to not reduce the pH, at least according to one HB member's experience: Corrosive Water

P.S.
Earlier I said that "there are no filters that specifically raise or lower just the alkalinity" and that's perhaps not quite true -- I forgot about the NuvoH2O. That system uses a cartridge that bleeds citric acid into the water, which would lower the pH, reduce the bicarbonate alkalinity and add citrate to the water. Sort of works like a constant citric acid descaler. I would avoid that system for espresso machine water because of the corrosion risk.

homeburrero wrote:Your 14 mg/L sodium would only be about 21 mg/L chloride if it were all NaCl, so your chloride is probably not problematic. And WAC resin decarbonizer does no carbonate reduction if if the water has no divalent cation (calcium and magnesium) - basically does nothing in that case.

Are you sure? BWT paper says that "calcium carbonate is kept", how does calcium become its own carbonate if not from dissolved bicarbonate?

homeburrero wrote:The Pentair Claris Prime literature is also lacking in detail. Of course it must remove an equivalent net charge of cations and anions. Interestingly it appears to not reduce the pH, at least according to one HB member's experience: Corrosive Water

That's very odd. My first reaction is to suspect measurement trouble.

homeburrero wrote:Earlier I said that "there are no filters that specifically raise or lower just the alkalinity" and that's perhaps not quite true -- I forgot about the NuvoH2O. That system uses a cartridge that bleeds citric acid into the water, which would lower the pH, reduce the bicarbonate alkalinity and add citrate to the water. Sort of works like a constant citric acid descaler. I would avoid that system for espresso machine water because of the corrosion risk.

There are many similar water conditioners. These ones only available for EU and US, though.
Problem is: no real information about what happens inside, even less than in BWT.

I am beginning to prepare myself for embracing RO, followed by BWT Bestmin (unless a better option for remineralising emerges). And with this GH/KH ratio, I can't even blend RO with untreated water.
I just tried to search. There are only two types of locally available RO systems:
* Fancy and expensive ones like Bluewater and BWT ROC
* Strange and fishy ones, like your typical Amazon nonames with a lot of strange filters and faux mineralisation.

old_bear wrote:Are you sure? BWT paper says that "calcium carbonate is kept", how does calcium become its own carbonate if not from dissolved bicarbonate?

I've not seen "calcium carbonate is kept" in any bestmax product literature. That statement would be true for the bypass water, so maybe that's what they are saying.

A WAC (weak acid cation) ion exchange resin is pretty straightforward. For each divalent cation that it removes it releases two H+ ions. In the case of BWT's patented magnesium technology in the bestmax premium there is a wrinkle in that some resin is preloaded with Mg++, so it sometimes replaces a Ca++ ion with a Mg++ ion. It doesn't matter to the resin what anions might be associated with the cations that it exchanges. If the predominant anion were Cl-, then you would get HCl, a strong acid. But hopefully the predominant anion is HCO3-, in which case it buffers the H+ to give an increase in carbonic acid and CO2 with lower bicarbonate. ( H⁺ + HCO₃⁻ ⇋ H₂CO₃ ⇋ H₂O + CO₂ )

old_bear wrote:I am beginning to prepare myself for embracing RO, followed by BWT Bestmin (unless a better option for remineralising emerges). And with this GH/KH ratio, I can't even blend RO with untreated water.

This makes me suspect you are trying to achieve a certain GH:KH ratio. Many people for whatever reason think that you should shoot for a 2:1 GH:KH ratio. But with your appx 107:125 ppm as CaCO3 tap water you are going to end up with a roughly 1:1 ratio whether you use a decarbonizer, or use RO with blending, or even if you use RO with a remin filter. With the first two I think you can get your water down to a GH:KH of around 40:50 ppm as CaCO3, which should be relatively non-scaling, machine healthy, and taste fine -- that number would be pretty close to the water what they use in recent WBC competitions. A remin filter using calcite, or calcite + corosex, or some sort of secret sauce BWT dolomite is going to give you low, but also nearly equal GH and KH numbers.

Interestingly enough, I tried BWT penguin bucket with magnesium sausages inside.
It made 6/7 GH/KH into 3/4. So, both values were decreased.

homeburrero wrote:...
This makes me suspect you are trying to achieve a certain GH:KH ratio. Many people for whatever reason think that you should shoot for a 2:1 GH:KH ratio. But with your appx 107:125 ppm as CaCO3 tap water you are going to end up with a roughly 1:1 ratio whether you use a decarbonizer, or use RO with blending, or even if you use RO with a remin filter. With the first two I think you can get your water down to a GH:KH of around 40:50 ppm as CaCO3, which should be relatively non-scaling, machine healthy, and taste fine -- that number would be pretty close to the water what they use in recent WBC competitions. A remin filter using calcite, or calcite + corosex, or some sort of secret sauce BWT dolomite is going to give you low, but also nearly equal GH and KH numbers.

The numbers you suggest seem close to what I get from a pitcher. It is very difficult for me to judge if GH/KH < 1 is really bad, but I don't like the taste of both waters yet.
BWT recommends their remin after RO. I'd expect it to increase GH more than KH.