Corrosive Water

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

#1: Post by mdecorte »

[Please forgive my lengthy post. This has taken me a bit to get to this point and I need some help]

I had a Isomac once and for the first year or so it was great but then it started breaking with leaks and parts breaking every few months. I was just using tap water. I blamed the breaks on the machine (retrospectively this may have been in error) and bought a La Spaziale Dream two years ago. Great machine but now every few months I'm back with replacing parts and fixing leaks. I practically have Chris' Coffee on speed dial.

I've also never been particularly happy with my shots. Thin, and either acidic and/or bitter. Never as good as the best shots I've had in NY. I've tried to fix every variable available (beans-check, align SJ grinder-check, pharos-check, EasyTamp-check, scale-check, scace-check, kinda running out of things to look at)

As I dig into this I think that I'm finally understanding that I have a corrosion problem. I thought it was scale, but no it's corrosion.

I've been researching this (the FAQ, Water for Coffee, and anything else I can) I *think* I understand the problem. I'm in Jersey City, NJ and the water at first glance seems pretty good but digging deeper it seems not so good.

The JC Water report: http://www.mysuezwater.com/sites/defaul ... _jCity.pdf

And testing my water using titration tests
pH 7.6
GH: 179
kH 71
looking good but....
Cl2- 95
Ca2+ 20
Mg2+ 0

My understanding is that the high CL2- is going to cause problems. I believe the low Ca2+ and Mg2+ helps explain my issue with shots.

Now I've been making matters worse with a Mavea Purity at 70% bypass

pH 6.7
Gh 107
Kh 26
Cl2- 95
(didn't measure the Ca2+, but I assume it's close to 0)

So now it's acidic and I've stripped out what little Ca2+ I had.

This education came from the WAC posts Warning: Chloride & sulfate levels with weak acid cation softeners (e.g., Everpure Claris)

[Side note, I've been replacing the Dream's steam boiler's temperature sensor every 4-6 months since I bought the Dream. This has been a common complaint for the Dreams. I'm wondering if most / all of these issues could be traced back machines with to Cl2- in the water and a WAC filter]

So what to do? I saw the new Claris Prime which somehow reduced Cl2- with the usual carbon block and filters. I found a dealer in FL and it came yesterday. It has an adjustable bypass with max bypass on 6 and min bypass on 1

http://www.pentairfoodservice.eu/produc ... php?id=175

with a bypass of 6 (lowest filtration setting)
pH 9+ (max of test)
GH: 71
kH 53
Cl2- 53
Ca2+ might be 0, the Red Sea tests turned color before adding any titrant
Mg2+ might be 0, the Red Sea tests turned color before adding any titrant

with a bypass of 1 (the recommended bypass for steam)
pH 9+ (max of test)
GH: 35
kH 35 (might be lower)
Cl2- 15
Ca2+ might be 0, the Red Sea tests turned color before adding any titrant
Mg2+ might be 0, the Red Sea tests turned color before adding any titrant

The Prime certainly is lowering the Cl2-, but I'm utterly confused how the pH has been raised. And of course the Ca2+ and Mg2+ are gone. I think this will stop my coorision, but the espresso it pretty bad.

In downtown JC we have a few good coffee shops (Dames, and 9 Bar). They are both very good at milk drinks, but I would not describe them as leading shops and I find their espresso isn't as good as the best I've had in NY. Dames let me look into their filter configuration and its just a carbon block.

I'm thinking that I either I should

move to RO water with a BWT BestMin (it is a Mg + Ca re-mineralizer but the specs are few). This is the proposal from La Marzocco
http://www.bwt-wam.com/en/Products/Page ... (BWTGROUP)
http://global.lamarzocco.com/en/the-new ... is-system/

or

make my own water and pump it with a flowjet. (a bit of an issue as I don't have power where the pump would go and I'm really spoiled by a plumbed machine)

So my questions:

- For my tap, is there agreement on my theory on Cl2- and corrosion?

- For my tap, is it effectively "soft" due to the low Ca2+ and Mg2+ and could explain my espresso woes?
Said differently, is my tap water actually fine and I just need a carbon block?

- The Mavea and WAC filters in general should be avoided given the Cl2-?

- For the Prime, why is the pH being raised?

- For the Prime, I think I'm returning it. Thoughts?

- Feedback on an RO and BestMin setup?

Thank you

User avatar
homeburrero
Team HB

#2: Post by homeburrero »

I don't think we've yet seen any discussion of that Claris Prime filter on this forum, and it is an interesting product. Your numbers on that are interesting and useful - thanks for posting those. Sorry to see that so far you have no answers. I'm no corrosion expert, nor a water treatment professional but I'll weigh in a little here FWIW and maybe others will follow on with more discussion.

First off, I assume that wherever you have written 'Cl2-' you are referring to chloride ion, probably intended to type 'Cl-'

Also, in terms of basic measurements, I think you should look closely at your Jersey City analysis, and throw out your Red Reef tests for Ca and Mg. Those tests are not very sensitive - are designed for aquarium people that are shooting for very high concentrations of Ca and Mg.

If you look at the water utility analysis, you will see:

Alkalinity 34-64 ppm (as CaCO3)
Total hardness 84 - 134 ppm (as CaCO3)
Calcium ion 18-26 ppm


You have enough there to estimate your Ca / Mg ratio

multiply Ca+2 ion by 2.5 to get Ca hardness:
=> Ca hardness = 45 - 65 ppm (as CaCO3)

subtract Ca hardness from total hardness to get Mg hardness
=> Mg hardness = 39 -69 ppm (as CaCO3)

To get Mg+2 ion concentration divide Mg hardness by 4.1
=> Mg+2 ion concentration = 9.5 - 17 ppm

So what I would do is just measure the tap water GH with a titration kit, and assume that maybe half is Ca hardness and half is magnesium hardness, and forget about using the Red Sea tests for this. In your measurements I think you are erroneously concluding that your Ca and Mg are gone. If you have GH, then you have Ca and/or Mg.

The water report also gives you conductance as well as actual TDS numbers
Conductance = 408 - 852 microMhos/cm
TDS (actual dry residue) = 189-334 ppm


To get a TDS meter reading, using a typical NaCl calibrated meter, just divide the conductance by 2
=> typical TDS meter reading = 204 - 426 ppm

If you want your bicarbonate concentration, divide your alkalinity by 0.82
=> [HCO3-] ion concentration = 44 - 78 ppm

The important reading in that report is that chloride number:
Chloride 93-134 ppm

It appears that your chloride tests are coming out in that ballpark (Seems you are not using theHach kit for this. Are your tests sufficiently precise at low concentrations? )

Your numbers for the Pentair Prime look like it is doing the job if you trust your Chloride tests. As you know, La Marzocco recommends less than 30 ppm, and Synesso recommends less than 15 ppm, and you are getting it down in that range with that filter. It does cause your alkalinity to drop a bit and I think ideally you want that to be 40 ppm or more for corrosion concerns.

The JC report says they are adding phosphates to keep the water non-corrosive. But I'm not sure these are effective at boiler temperatures.

Re some of your specific questions:
mdecorte wrote:- For my tap, is there agreement on my theory on Cl2- and corrosion?
I think it's fairly well accepted that chloride is associated with corrosion, especially pitting corrosion in copper/brass and in stainless steel. Search the forum for rpavlis' comments using keywords +chloride +corrosion, also see this article from Pentair: /downloads/ ... pdated.pdf
mdecorte wrote: For my tap, is it effectively "soft" due to the low Ca2+ and Mg2+ and could explain my espresso woes?
Said differently, is my tap water actually fine and I just need a carbon block?
It would be great with a simple carbon filter, if only you didn't have that chloride problem. Note that your tap's Ca hardness is in the SCAA superior brew range. And the alkalinity is good. If you are a shop, trading in your espresso machine every 2-3 years, I think carbon-only filtration might be the way to go.
mdecorte wrote:- The Mavea and WAC filters in general should be avoided given the Cl2-?
Probably. Your bicarbonate is less than 100 and your chloride is above 80, so Pentair (see link above) would not recommend it.
mdecorte wrote:For the Prime, why is the pH being raised?
I think that's the nature of the anion exchange resin in that filter. It's exchanging hydroxyls (OH-) for chloride, sulfate, etc. . Kind of the opposite effect of the cation resins (WAC) that exchange cations with H+ ions. After exposure to atmosphere, it should pick up CO2 and the pH may drop a bit.
mdecorte wrote: - For the Prime, I think I'm returning it. Thoughts?
- Feedback on an RO and BestMin setup?
Seems either would work. I'd check with vendors about cartridge replacement on the Prime when you have 200 - 400 ppm TDS, it may get expensive. I think the RO + remin route would give me more peace of mind when it comes to the corrosion concerns.
Pat
nínádiishʼnahgo gohwééh náshdlį́į́h

Lacoffee

#3: Post by Lacoffee »

+1 homeB. You can get an active carbon chlorine/chloramine RO stage easily enough. I would do RO and remin just for he ease of use and piece of mind. It won't matter what goes in as long as you effectively remin on the way out.

See http://www.freedrinkingwater.com/ww-fi- ... ilters.htm

A few manufacturers have similar tech.
And the bwt best min seems a great solution post filter. I have the standard APEC RO remin cartridge and it doesn't quite bring my numbers up to where I want them so I had to to a blend with tap that comes through a bwt bestmax premium. But I think the bwt bestmin in line would accomplish the same thing.


For me the advantages of the RO are too big to do anything else. It's piece of mind plus the fridge, ice, drinking water spigot, espresso, and dishwasher. Unbelievable what RO water does for dishes.

Check out the gro line of pentair membranes too because they are so efficient.
Andrew