La Marzocco’s 70–100 hardness band is not Simonelli USA’s under-50 ceiling

Espresso writing often treats “good machine water” as one hardness band that somehow coincides with “SCA water.” In the manufacturer and free-standard documents examined here, that collapse does not survive. La Marzocco publishes a total-hardness window of 70–100 ppm. Nuova Distribution USA’s Standard Dealer Limited Warranty requires water hardness below 3 grains per gallon or 50 ppm. The free SCAA/SCA Water for Brewing tables publish calcium hardness 17–85 mg/L. Those three hardness statements do not name one shared interval, and two of the machine figures do not even overlap each other.

The finding is documentary identity: which source examined here carries which hardness, alkalinity, TDS, pH, and halogen line, under which kind of claim, and where the labels themselves refuse to be interchangeable.

Three kinds of claim

Those rows are not one “espresso water standard.” The first two are machine-water requirements from different OEMs’ USA documents examined here. The third is a specialty-coffee brewing-water table. None of the three documents claims to reprint the other two.

What La Marzocco publishes

The La Marzocco USA PDF examined here is titled La Marzocco Water Specification. Its table states, among other rows:

The same numeric hardness, alkalinity, TDS, pH, chlorine, and chloride bounds appear in the table on La Marzocco’s Ireland technical-questions page titled “La Marzocco Water Specifications,” introduced there as parameters water “should fall within” for “optimum machine performance.”

Two label facts matter immediately. The hardness row is Total Hardness, not calcium hardness. The halogen corrosion row that carries a 30 ppm ceiling is Chloride, printed separately from the free/total chlorine maxima. The PDF also recommends caution when using sodium- and hydrogen-based ion-exchange water softeners. That is a softener-stance statement, not a hardness number, and it will matter against the Simonelli USA warranty below.

What Nuova Simonelli USA publishes

Nuova Distribution USA’s Standard Dealer Limited Warranty examined here contains a WATER REQUIREMENTS paragraph that is not optional prose. Softener installation is mandatory when the espresso machine is fed with water harder than 3 grains per gallon or 50 ppm. The same paragraph requires filtration below 1.0 micron, TDS between 50 and 250 ppm, alkalinity between 10 and 150 ppm, chlorine less than 0.50 ppm, and pH between 6.5 and 8.5, and states that failing to meet and maintain those levels voids the entire warranty.

The Simonelli USA warranty web page repeats the water list in bullet form, including “Water Hardness: Less than 3 grains per gallon or 50 parts per million,” “Total Dissolved Solids: 50 - 250 parts per million,” “Alkalinity: 10 - 150 parts per million,” “Chlorine: Less than 0.5 parts per million,” and “pH: 6.5 - 8.5.”

The Aurelia Wave 2 Group installation-requirements sheet from Simonelli USA examined here carries the same TDS, alkalinity, chlorine, pH, and filtration figures and states “Water hardness 3gpg or 50 ppm.” That sheet does not reprint the warranty’s comparative “less than” wording. This article therefore treats the warranty’s “less than 50 ppm” / softener-above-50 rule as the explicit ceiling statement, and notes the Aurelia Wave line as a same-distributor installation sheet that names the same 3 gpg / 50 ppm figure without the comparative.

None of these Simonelli USA documents examined here prints a total-hardness minimum of 70 ppm. None prints chloride 0–30 as a separate row.

The hardness bands do not overlap

Read as published numeric constraints on a hardness figure expressed in ppm:

• La Marzocco’s table examined here requires total hardness at least 70 and at most 100.
• Nuova Simonelli USA’s warranty examined here requires hardness below 50 (and mandates a softener when hardness is higher than 50 ppm / 3 gpg).

There is no integer ppm value that is both ≥70 and <50. Under the sheets examined here, a single hardness reading cannot satisfy both machine-water hardness statements at once.

That non-overlap is the load-bearing reconciliation. It does not require converting grains, ranking manufacturers, or deciding which boiler metallurgy is right. It only requires reading the minima and maxima the documents print.

The free SCAA/SCA table does not rescue a shared band. Its calcium-hardness acceptable range is 17–85 mg/L. Even if someone ignored the calcium-versus-total label and treated every “hardness” number as interchangeable — which these documents do not authorize — 70–100 is not 17–85, and “under 50” is not 17–85 either. SCA’s target 68 sits inside its own calcium range; it is below La Marzocco’s total-hardness minimum examined here and above Simonelli USA’s warranty ceiling examined here.

Labels that refuse to collapse

Hardness is only the clearest split. Adjacent rows show the same documents refusing a single “water spec” vocabulary.

Hardness name. La Marzocco prints Total Hardness. SCAA/SCA print Calcium Hardness. Simonelli USA prints “Water Hardness” / “hardness” without saying total or calcium in the warranty and Aurelia Wave texts examined here. A reader who merges those labels into one measurand is doing work the sources do not do.

Alkalinity width. La Marzocco: 40–80 ppm. Simonelli USA: 10–150 ppm. Free SCAA/SCA: target 40 mg/L, acceptable “at or near 40 mg/L.” The machine bands are wide; the free brewing table’s acceptable alkalinity wording is not a 10–150 or 40–80 interval.

TDS. La Marzocco: 90–150. Simonelli USA: 50–250. Free SCAA/SCA: target 150, acceptable 75–250. Simonelli USA’s TDS window is close to the free table’s acceptable TDS band; La Marzocco’s is narrower and raised at the floor.

pH. La Marzocco: 6.5–8. Simonelli USA: 6.5–8.5. Free SCAA/SCA: 6.5–7.5. The machine documents open the upper bound past the free brewing table.

Chlorine versus chloride. La Marzocco tabulates free chlorine, total chlorine, and a separate chloride maximum of 30 ppm. Simonelli USA’s warranty examined here and Aurelia Wave sheet state chlorine less than 0.50 ppm and do not print a chloride row in those water lists. Chlorine and chloride are different published analytes. Attaching La Marzocco’s 30 ppm chloride ceiling to a chlorine line, or Simonelli USA’s 0.5 ppm chlorine ceiling to a chloride line, is a wrong attachment.

Softener stance. La Marzocco’s specification examined here recommends caution with sodium- and hydrogen-based ion-exchange softeners. Simonelli USA’s warranty examined here makes a water softener mandatory above 50 ppm / 3 gpg hardness. Those are opposite published postures toward softening, not a shared filtration recipe.

Bounded conclusion

In the sources examined here, espresso-relevant published water figures do not form one hardness band. La Marzocco’s total-hardness 70–100 ppm window and Nuova Simonelli USA’s under-50 ppm warranty ceiling do not overlap. The free SCAA/SCA calcium-hardness 17–85 mg/L brewing table is a third kind of claim, not a reprint of either machine sheet. Alkalinity, TDS, pH, chlorine-versus-chloride, and softener language diverge with the same documents.

What this check does not establish

It does not establish which hardness band is better for taste, scale control, or corrosion in any particular boiler.

It does not establish a global Nuova Simonelli factory water standard outside the USA distributor documents examined here warranty, warranty page, and Aurelia Wave installation sheet.

It does not establish that La Marzocco’s Ireland page supersedes or is superseded by the USA PDF; it only records that the numeric table examined here matches.

It does not establish magnesium preference, a mineralisation recipe, or which unread SCA Water Quality Handbook rows a machine maker should follow.

It does not edit or replace the site’s separate articles on what the free SCAA/SCA brewing-water tables cite, or on SCA 310’s home-brewer test-water summary.