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How pleased are you with ZeroWater solution?
And were split to this new topic by moderator on Jan 23

homeburrero wrote:I use powdered CaCO3, MgCO3, and KHCO3. I add about 1g of each to a 750 ml swingtop stoppered bottle for my concentrate. That concentrate is cloudy with undissolved CaCO3, so I need to shake well before using. I add a shotglass (~44ml) of that to 3L of purified water in a gallon glass jar get my brew mix. If I let that sit a while all precipitate dissolves fully - I never see precipitate in the bottom of the gallon jar. Generally on my Giotto I'm even lazier - every night I simply fill the reservoir direct from the Zerowater jug, then followup with a partial shot of my concentrate (shooting for roughly 40 ml per full reservoir tankfull.)

I'm not a true believer in this mix. It's easy for me, but I'm not convinced it's any better than simple 100 mg/L KHCO3 (rpavlis) water. Like the rpavlis water, my water has good alkalinity and zero chloride or sulfate, which appeals to my paranoia about brass and copper corrosion in my older espresso equipment.

Perhaps off topic, but I've tried to use this recipe and wasn't very successful.
I've created the concentrate, which was indeed cloudy.
After letting it sit for a few days in the fridge, the CaCo3 sank down to the bottom of the bottle.
Just before preparing the water, I shook the bottle well and the water became cloudy again.
Then I measured 44ml to be added to 3L of distilled water.
My resulting water measured 1-2dKH and also GH was rather low.

What am I doing wrong? Should I have poured the 44ml quicker? How fast does the CaCo3 sink after shaking the bottle?
Is it possible that I've made some mistake when creating the concentrate (though I was very careful while preparing it)?
Any idea or advice?

MonLon wrote:Perhaps off topic, but I've tried to use this recipe and wasn't very successful.
[...] Is it possible that I've made some mistake when creating the concentrate (though I was very careful while preparing it)?

As long as you get the amounts right I think you should be OK. I give it a good shake and immediately pour off (less than 2 seconds) my shot of concentrate, and over time my concentrate bottle doesn't seem to get more or less concentrated. Everything that goes into my bottle eventually goes into the reservoir so it has to average out. I just did a careful mix of a new 3 liters, and tested myself (API GH and KH kit, boosted to 10 ml sample (9.8 mg/L CaCO3 equivalent per drop) , and came out as I'd expect - about 6 drops for KH and about 4 - 5 for GH.

Some ideas - store your salts in sealed containers and dry space. All are mildly hygroscopic and can absorb moisture in humid environments. The KHCO3 will form hard lumps if it absorbs a little moisture. But I think this would not drop you much. I oven-baked some lumpy KHCO3 once and found that it had gained less than 5% moisture.

Also, for the API GH test I think you need to give the mix a day or two before titrating - make sure it's nice and crystal clear and the carbonates are well dissolved over to bicarbonate, Ca(HCO3)₂ otherwise I think you won't see that orangish starting color that goes greenish at the endpoint. I expect the Hach total hardness kit may work better here.

Many thanks Pat.
Helpful as always
I'll give it another go and hope it will turn out better.

homeburrero wrote: and micronized MgCO3 by Bulk Supplements.

For those who like calculating stuff keep in mind this isn't simple MgCO3 but the dypingite version with formula: 4MgCO3 - Mg(OH)2 - 5H2O

You might need to adjust your weights accordingly.

(They don't say it's dypingite anywhere on the packaging/website but it's rare to see simple MgCO3 - at least when I've looked for it. You can also see that they say you get 385mg of magnesium for 1540mg of powder which is inline with the molar masses in the dypingite formula assuming I haven't made a dumb formula error [certainly wouldn't count it out!])

Thanks Lewis!

Power Freak wrote:keep in mind this isn't simple MgCO3 but the dypingite version with formula: 4MgCO3 - Mg(OH)2 - 5H2O

I had looked into it and thought the Bulk Supplements product was simple pure magnesium carbonate, but I think you are right here - they do say their product is 25% elemental Mg, and say it again with that 385 mg in 1540 mg of powder, which would be spot on for dypingite.

Power Freak wrote:You might need to adjust your weights accordingly.

Fortunately it comes out approximately the same - pure MgCO3 would be closer to 29% elemental Mg. Making the correction to my recipe with 1 gram of this magnesium powder, my total hardness in the final mix should be 41 mg/L rather than 44 mg/L CaCO3 equivalent, and alkalinity 51 mg/L rather than 54 mg/L.

P.S.
For chemistry geeks, note that even though there is no carbonate ion in the Mg(OH)₂ of the dypingite, once added to water it will be there. Essentially it sucks up some carbonic acid. The pH goes up temporarily until the carbonic is replenished via CO2 from the atmosphere. Here are the reactions
CO₂ + H₂0 -> H₂CO₃ (carbonic acid)
Mg(OH)₂ + 2H₂CO₃ → Mg(HCO₃)₂ + 2H₂O