What are these black deposits from the water tap?

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

#1: Post by Ahmad H. »

These black deposits coming out the hot water tap from my Linea mini. Not a lot coming out.

Is this scale forming? Or just some content from the steamed water that forms at the button on the steam boiler?

Should I be worried?

I use RO filtration system with good specs for espresso machines and coffee.

Nunas
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#2: Post by Nunas »

Just a guess, but since you're using an RO system, it could be carbon particles from the final filter in the RO.

Pressino

#3: Post by Pressino »

Or if pure RO H20 without added minerals is used, it could be preciptated products of corrosion from exposure of the machine's innards to RO water, which is an excellent solvent. Probably not that but...not entirely out of possibility. :shock:

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BaristaBoy E61

#4: Post by BaristaBoy E61 »

Interesting that just this morning my wife drew some hot water into a white ceramic cup from the hot water spigot of our DB machine that looked exactly as illustrated in the picture of the OP. We're using a BWT Best Max Premium filter with our direct plumbed machine.

I suspected it might be some oxide from the boiler wall but not absolutely sure.
I'll wait for answers from more knowledgable members.
"You didn't buy an Espresso Machine - You bought a Chemistry Set!"

Ahmad H. (original poster)

#5: Post by Ahmad H. (original poster) »

Not pure RO, RO with added minerals that produces yhe below water specs (approximately):
TDS ~90-100
Alkilanity ~ 52
PH ~ 7.3
Total hardness ~ 45

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homeburrero
Team HB

#6: Post by homeburrero »

This is a really frequent question on HB - - If you search this site about "black specks" you'll get about 80 hits with many of them showing a picture much like yours, and practically none of them with a conclusive answer about what the specks are.

My best guess in this case agrees with Nunas' -- it's likely charcoal dust from the finishing filter of the RO. (You'll notice that many folks who report these black specks are not plumbed in and report seeing see them in their reservoir.) It's almost surely not scale or similar precipitate from water minerals, and unlikely to be an oxide from copper or steel corrosion. I think If some of your particles were much larger a reasonable guess would be that they might be bits from a deteriorating seal or o-ring.

Nothing to worry about in my opinion.

P.S.
What TDS do you read on the water from the tap after it has cooled to room temp? If you steam a lot and rarely purge or drain the steam boiler, then you can expect highly concentrated water in the boiler, which might produce scale or precipitate, but not these black specks.
Pat
nínádiishʼnahgo gohwééh náshdlį́į́h

Ahmad H. (original poster)

#7: Post by Ahmad H. (original poster) »

Thanks for the replay!

It's strange that these could be charcoal. I'm pretty positive that the water that comes out from the filter is crystal clear with no bits at all (unless they are hard to see with naked eye if not concentrated?)

I do purge the steam water on weekly basis and I don't steam much (maybe 1-2 milk drinks per week). The TDS from the steam boiler after water cools down is around 110.

I was worried that these could be bits from the heating element breaking down due to corrosion or something like that.

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redbone

#8: Post by redbone »

I use a Doulton washable ceramic filter as my final filter. Traps fines including charcoal dust.
Between order and chaos there is espresso.
Semper discens.


Rob
LMWDP #549

Ahmad H. (original poster)

#9: Post by Ahmad H. (original poster) »

Little update.

I did a lot of steam boiler flushing, but the stuff keeps coming out. This is differently not scales, I don't think it's charcoal cuz it's only coming from the steam boiler. I don't see this in brew boiler or anywhere else where I use the water.

I'm using an RO system with added minerals (Eccosoft, which is a brand in BWT).

Not sure if I should be worried or just ignore it.


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BaristaBoy E61

#10: Post by BaristaBoy E61 »

Ahmad H. wrote:Little update.

I did a lot of steam boiler flushing, but the stuff keeps coming out. This is differently not scales, I don't think it's charcoal cuz it's only coming from the steam boiler. I don't see this in brew boiler or anywhere else where I use the water.
That might make sense because the thermosyphon pipes coming off the brew boiler to the group are probably not located at the bottom of the brew boiler as they are for the hot water spigot from the steam boiler.
"You didn't buy an Espresso Machine - You bought a Chemistry Set!"