Should I descale my E61?

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RyanJE
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#1: Post by RyanJE »

Hello All,

I have had my QuickMill Alexia (SBDU) for about 6 months now. I have always used Gerber Pure nursery water, which should be soft enough to prevent scale. Just in case I pulled the mushroom to check for scale and picture is below. To my surprise I am still getting scale! Is this enough to warrant a descale? Should I leave it and check back in 6 more months?



My concern is two fold. 1. The QuickMill manual says do not de-scale the machine. 2. I dont want to cause more issues by descaling, but also dont want to let it go and have issues down the line.

Please HELP! Thank you in advance.
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Nunas
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#2: Post by Nunas »

The amount of scale on your photo is not huge. However, I'd look at the water analysis. Gerber blocks me from their site so I can't check, but I do know that their water has added minerals. Perhaps adding some RO water would be a good idea. One can even run pure RO water through the machine (or make coffee with it for a while), which will reduce scale, although some report that pure RO water can lead to overfill (I've never experienced this).

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RyanJE (original poster)
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#3: Post by RyanJE (original poster) replying to Nunas »

I've personally tested the Gerber Water with Alkalinity and Hardness reagent test kits. According to Jim's water FAQ, I should be fine as the Alkalinity is about 17-34PPM and hardness about 70PPM (these tested results are a bit higher than their max spec interestingly). About 100TDS

COULD this alternatively be Corrosion? I read some places that blue green deposits can actually be corrosion.
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cannonfodder
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#4: Post by cannonfodder »

RyanJE wrote:Hello All,

Is this enough to warrant a descale? Should I leave it and check back in 6 more months?
No, check back in 6 to 12 months.
Dave Stephens

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keno
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#5: Post by keno »

Blue and green deposits are usually an indication of copper corrosion. You may want to run some tests on your water to check for conditions that might cause copper corrosion (eg, high sulphates, low pH).

DaveC
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#6: Post by DaveC »

cannonfodder wrote:No, check back in 6 to 12 months.
Lubricate the O ring with a bit of silicon grease e.g. Dow 111 or similar and put it make in the group...then do what he said above....you're over thinking the whole thing.

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homeburrero
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#7: Post by homeburrero »

Agree with the above. Looks like no scale, but some small spots of copper salt deposits, probably copper carbonate, which is fairly common, especially in spots on the mushroom where the plating has flaked off. You can scrub this green stuff off, or soak in a 50:50 vinegar solution to dissolve it.

As keno says, these deposits may indicate a corrosion concern. (Also check out this post by chem professor Pavlis related to these deposits: 1977 La Pavoni Europiccola with green deposits/scale .) Right now Gerber won't let me look at their water analysis, but if it is at a low pH, with significant chloride and sulfate, and with low alkalinity, the water could contribute to corrosion. With your measure of a hardness of 70 ppm as CaCO3, and alkalinity of only 25 ppm as CaCO3, it appears that you have 40-50 ppm of 'permanent' hardness that is not associated with carbonate ion, which usually means it is associated with chloride or sulfate ion.

You could try spiking your Gerber water with a tiny bit of bicarbonate solution so as to to bring the alkalinity up to above 40ppm, which should raise the pH and possibly help with corrosion. Then pull the mushroom again in 6 months and check.
Pat
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RyanJE (original poster)
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#8: Post by RyanJE (original poster) replying to homeburrero »

Here is the Gerber spec, although my tested results for Alkalinity and Hardness are slightly higher than their "Max" stated here.

Alkalinity, Total as CaCO3 13-17
Aluminum t ND
Boron ND
Bromide ND
Calcium 10-13
Chloride t17-24
Copper ND
Iron ND
Magnesium 5.8-6.4
Manganese ND
pH (pH Units) 7.4-7.6
Potassium 13-17
Silver ND
Sodium ND-1.3
Specific Conductance @ 25C (umhos/cm) 160-200
Sulfate t 22-24
Total Dissolved Solids 82-110
Total Hardness (as CaCO3) 49-59
Zinc ND

For now I will leave it be and check back in 6-12 months. Here I thought I was doing right using the Gerber Pure for my machine! I want it to last as long as possible.

What about if I started using 70/30 water for espresso instead (rather than spiking Gerber Pure)?

Link

https://s3-ap-southeast-2.amazonaws.com ... recipe.pdf
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homeburrero
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#9: Post by homeburrero »

RyanJE wrote:What about if I started using 70/30 water for espresso instead (rather than spiking Gerber Pure)?
That would work. The sulfate [SO4--] concentration of 70/30 would be 22 mg/L - about the same as the Gerber, but you would have no chloride, so that would be a plus. You would have about half the total hardness of the Gerber, which some might argue could affect the extraction and taste. And you'd have nice alkalinity which should help with concerns about corrosion.
Pat
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RyanJE (original poster)
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#10: Post by RyanJE (original poster) »

THANK YOU everyone on this chain! All have been tremendously helpful as usual.
I drink two shots before I drink two shots, then I drink two more....

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