My water is screwed

[Buckeye_Hydro]

No, I get that but there are plenty of systems that don't include that and frankly it seems like another ongoing cost that for brewing use that can be avoided with a simple float in the kettle. I'm also a figuring we go through all the trouble to RO out just about everything from the water and then be willing to accept some plastic getting added back in for the sake of storage.

If a pressure tank can be avoided, best to do so... and mount a float in your kettle as you mention. You'll get water out of the RO faster, the permeate will be more pure, and you'll send less water down the drain.

If however, the user also wants the RO to feed an ice maker, or a refig, or a faucet, a pressure tank w/ taste and odor filter will be required. A permeate pump can address some of the complications of having a pressure tank.

 

[Mack]

That is the purpose of the taste and odor filters you see on all systems that have a pressurized storage tank. They are simple in/out filters that contain GAC.

Would you consider this an example of a taste and odor filter? I've got a bunch of these on hand (use them for my ice machines)...

https://www.amazon.com/dp/B07NL2Z7MN?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_13&th=1

 

[day_trippr]

That'll work. My RO system has a "taste and odor" filter for the pressure tank output and it's simply GAC like those...

Cheers!

 

[Buckeye_Hydro]

Would you consider this an example of a taste and odor filter? I've got a bunch of these on hand (use them for my ice machines)...

https://www.amazon.com/dp/B07NL2Z7MN?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_13&th=1

Yep! Far from the best for use as a prefilter like you are using it, but just fine for a post filter/taste and odor filter.

 

[Peebee]

I think you mean to say that alkalinity is calculated while the other values are directly measured. Which is all well and good but doesn't really answer my question so I will rephrase based on your comment - how is it possible to measure 14 ppm CaCO3 (hardness) and then calculate 217 ppm CaCO3 (alkalinity)? If hardness is also a calculated value based on a different formula, then how do we reconcile such different results for parameters that are reported in the same units of the same compound?

I think everyone ignored you?

Including @mabrungard, which is a shame because he has an excellent post on "as CaCO3" somewhere (his own Web site I think?).

I mean "as CaCO3", though for some reason people like to forget to put "as". It's "pretend", or "an equivalence", a damn stupid one if you ask me, for just the reasons you provide an example of. Although there are good historic reasons for it (when sums were done with a stub of pencil on an old ***-packet. [EDIT: Oh ... a bit of cross-Atlantic difference of meaning: Try "cigarette"?]

When you see "CaCO3" don't automatically think "calcium carbonate". It's just a "unit" like "ounces". Makes more sense if people didn't leave out the "as". Find Martin's article (damned if I can), it's very good.

 

[Peebee]

@mac_1103: Cor! Look what I remembered! From the depths of my (notorious?) water "pre-processor" (the "Defuddler"):

Sodium and Potassium referenced "as CaCO3"! There was a reason for it ... honest! But if that ain't confusing, what is.

 

[Peebee]

I was doing something with that wretched "Defuddler" spreadsheet of mine, and I remembered this thread and @mac_1103's frustrations with it, so I thought I'd chuck this piece in:

@mac_1103 I understood alkalinity to be a measurement rather than a considered value. Based on the formula for total alkalinity ≈ 50.0435(Ca/20.039 + Mg/12.153 + Na/22.99 - Cl/35.453 - SO4/48.031).

My results are 219ish, based off of using a quantity of "0" for and SO4.

Whoa! What a lot of complicated screwy numbers! That's got to be more correct than I'm saying?

Except ... not at all! It's doing the same thing. All the screwy numbers are changing things back-and-fro with "equivalence" measurements. I recognise some of the numbers; 20 and 50 (20.039 and 50.0435 wouldn't be used on the back of a fa... ah-ah ... cigarette-packet), so I can see "as CaCO3" is involved. And "equivalence" means "the same". So, you can use simple arithmetic (plus and minus) with them. Even someone brain-damaged can do it (that's not being politically incorrect ... I am brain-damaged!). Let me roll out my forever-malevolent (it's actually quite useful!) "Defuddler" spreadsheet:

So there's lots going on in that snippet of the spreadsheet, but the first line is much the same as the quote it follows. The same elements and compounds, the same "result" - "Alkalinity" - I've just displayed the resulting units ("mg/l" which is "ppm" here). The "equivalents" are worked in the depths of the spreadsheet, along with the dead-simple sums ... add the cations together ("1+2=3" fashion!), add all the anions, subtract the anions from the cations and what you're left with is remaining anions that represent "alkalinity", as near as damn-it.

My spreadsheet will incude things like the potassium and nitrates shown above, but that's just nit-picking as far as drinking water is concerned.

The "Alkalinity" is displayed in four different units, of which I have a preferrence (as do most of your water companies) for "as bicarbonate", which is reasonble as 95-97% of alkalinity is bicarbonate (HCO3) in drinking water.

And the purpose of this post? Just to prove that the often repeated addage, "water chemistry is complicated" is nonsense at this level. It's just those scary long numbers, the outlandish units (like "mEq/L"), and most of all the out-dated technologies like "Hardness" and "as CaCO3" (even "mEq/L" that I use a lot is outdated amongst the big boys) that causes the confusions.



And why do I bother to write these loooong drawn out posts. I did mention I'm "brain-damaged" (stop it, horrid term, ... brain-injured). Well these long drawn out posts are one way I use to drive things home in me 'ead.

 

[Peebee]

I was closing a Web page (support.hach.com) and noticed this little comment concerning "equivalents". I felt it was worth saving (it's relevant to my last post in this thread) ...

... This calculation does not change the concentration of <del> in the sample, it only changes the value in relation to the units it is expressed in.

For example:
Changing a height from 6 feet to 72 inches, or to 183 cm, does not change the actual height, it only changes the units in which it is reported. They are all mathematically equivalent.