Talk:Hard water

Hi, There is a formula missing that was in the old section:

CaCO_3(s) + H₂O_(l) + CO_2(g) ⇌ Ca²⁺(aq) + 2HCO₃^-_(aq)

Please put it back!

--Lenny B Good (talk) 06:31, 20 February 2008 (UTC)

What is the level of hard water in Charlottsville, Virginia Beach, Richmond, Well water, and Washington D.C.?

Lead?

Hard water usually consists of calcium, magnesium ions, and possibly other dissolved compounds such as bicarbonates and sulfates.

Pardon? Is there any water in this hardness? uFu (talk) 05:33, 10 January 2008 (UTC)

Are you serious???--98.240.153.125 (talk) 21:45, 3 May 2010 (UTC)

Hard Water

New Definition for hard water has been added to this topic. If any one needs any kind of help in any topic may email to '''online.vcet@gmail.com''' --Thooyavan 04:10, 4 December 2007 (UTC)

Permanent Hardness

An anonymous contributor asserted this:

"It has to be in more then 50gms/dm3 in concentration to be called permanent hard water."

Any back-up/citation for this?

WLD 10:20, 25 March 2006 (UTC)

http://www.keidel.com/resource/water/hard.htm

Hot Lime Softening

In industrial processes, boiler operation in particular, water is often softened with a Hot-Lime softener, I have done superficial wiki searches and haven't come up with anything referring to hot-lime softening. If anyone can clarify this for me, that'd be great. Otherwise, I will create an article about Hot-Lime softeners. 161.19.64.5 02:25, 17 April 2006 (UTC)

Stain?

The deposites of Calcium, Limescale, ect. left after hard water has been on a surface and evaporated is often refered to as hard water; however, this is ironic as there is no longer any water present.

Isn't this called a hard water stain? PrometheusX303 20:10, 16 May 2006 (UTC)

Apparent Error in Article

The conversion from mg/L of calicum to other hardness scales seems to be bogus. For example, the conversion in the article to German degrees says that 3mg/L of calcium equals 21°dH. According to information I have from a water-testing kit, 21°dH is very hard water. However, other sources on the web say that 3mg/L is very soft water. Perhaps instead of "divide by", the author meant "multiply by".

Read the article carefully - it does not say what you think it does. 21°dH converts to 150 mg/L, which is 'Very Hard'. 21 divided by 0.14 is 150. WLD 21:10, 15 October 2006 (UTC)

It is difficult here, not to mix mg/l of calcium-ions and mg/l of CaCO3.

21°dH converts to 3,8 mol/l CaCO3, which means 380 mg/l CaCO3 or 210 mg/l CaO or 150 mg/l Ca++. This is why I prefer mol/l.

In the section "Hard water in australia" it should - in my opinion - say "as Ca" because 100 mg/l CaCO3 are 1 mol/l or 5,6 °dH which is not hard at all.

As being german, I find it confusing to find data in water analysis sheets like: "5 ppm CL- as CaCO3". I can't make sense of that.I. G. Bauer 16:32, 4 September 2007 (UTC)

I agree that it is confusing, and I too would like a subject matter expert to contribute and clarify/tidy up. Sorry I can't. WLD^talk|edits 09:10, 7 September 2007 (UTC)

Doubtful etymology

"Earlier generations coined the phrase 'hard water' because it made cleaning difficult. Hardness is caused by compounds of calcium and magnesium. All freshwater sources contain calcium and magnesium in varying quantities."

That sounds suspect - the opposite of hard water is soft water, not easy water, plus other languages use words for "hard" water which don't include the meaning "difficult". Zocky | picture popups 02:27, 7 November 2006 (UTC)

The correct etymology is from the hardness of beans soaked or cooked in various waters. I first came across this in a chemistry book I read over 40 years ago. The fact that it does vary the hardness of beans is easily verified. 216.179.3.33 16:53, 9 March 2007 (UTC)robgood@bestweb.net

If you can cite the book, fine, but it is an extraordinary claim. I would suggest that the book in question may well be incorrect, but as Wikipedia is based on verifiability, not truth, if you can cite it, it would belong in the article. Regards, WLD^talk|edits 17:09, 9 March 2007 (UTC)

I checked the referred pdf, and the references given in it. The given pdf does not say the origin of the term 'hard water' is from the behaviour of cooked beans. Of the three references cited in the pdf, the two web references are no longer valid. A better citation would be required. Best. WLD^talk|edits 18:31, 9 March 2007 (UTC)

Funnily enough, my GCSE chemistry folder from Oxford Open Learning makes the same claim about water used to soften beans, and adds it originated during the American Civil War. So naturally I came here for verification. It is either the least known brilliant story, or just an urban myth. —Preceding unsigned comment added by 199.245.34.11 (talk) 02:53, 24 May 2009 (UTC)

Advertisement

This seems to be a marketing exercise for water softeners - "unsightly spots on dishes" indeed. Colonel Mustard 03:08, 28 November 2006 (UTC)

Conversion to/from Clarks seems off

I have also encountered a problem with the conversion table (under Types of Measurement). The formula x Clark degrees / 0.175 = y ppm seems off.
In the conversion table it says conversion to mg/L calcium: divide by 0.175. Put to practice: I have 1 Clark degree. To get mg/L I divide by 0.175, i.e. approx. 5.7 mg/L, which should be the same as 5.7 ppm. Yet in the next line One degree Clark corresponds to one grain of calcium carbonate in one Imperial gallon of water which is equivalent to 14.28 parts calcium carbonate in 1,000,000 parts water. – i.e. 14.28 parts per million.
The University of North Carolina's Dictionary of Units Measurement also states the Clark degree is defined as 1 part of calcium carbonate per 70 000 parts of water; this is about 14.3 parts per million (ppm). And Global Water Instrumentation, Inc. has a table stating that 1 ppm = 0.07 Clark degrees, which corresponds to 1 Clark degree = 14.3 ppm.
Could someone check this pls? I’m just a translator attempting to convert French water hardness levels into English ones. Merci beaucoups. 85.207.119.184 16:26, 17 December 2006 (UTC)

You are correct. Formerly, the article tried to define these units and conversion factors in terms of calcium *ion* concentrations, rather than as concentrations of the actual calcium compounds (CaCO3, CaO) used in the original definitions. While not strictly speaking incorrect, these descriptions were confusing, imprecise, and unhelpful. This has now been fixed in the article.24.72.118.223 (talk) 00:22, 27 January 2009 (UTC)

Vandalism Corrected

I have corrected vandalism within the first line of the article. Please view the revision history for details. Chrisbrl88 08:38, 25 February 2007 (UTC)

World-wide view

How is hard-water viewed in non-English speaking parts of the world? Why do we need a warning tag that warns us that this is not a global world-view on Hard Water? Do people in China doubt that Australia has hard water issues? I don't get it, so I'm removing the tag. Vivaldi (talk) 05:33, 25 March 2007 (UTC)

Hard, heavy, WTF's the big difference anyway?

In the early Flash comics of the 1940s, Jay Garrick's fantastic speed is attributed to inhaling "hard water fumes" that render him a "freak of science". See here for comical mumbo-jumbo. Asat 02:40, 17 September 2007 (UTC)

Sounds like somebody had hard water confused with heavy water. Not that heavy water has "fumes" (it has vapor or steam, just like regular water) or is going to turn you into a "freak of science". But it is slightly radioactive, so a reference to it makes a little more sense. In a comic book, that is! Isaac R (talk) 20:21, 6 October 2008 (UTC)

Magnetic Water Conditioners

I am aware that there are magnetic appliances that can remove the hardness in water. If some one knows more about this, I feel it would be beneficial for it to be included in this article. —Preceding unsigned comment added by Claughton (talk • contribs) 16:38, 7 February 2008 (UTC)

The usefulness of magnetic appliances is still in doubt. The situation is well described on the following webpage:[1]. At this point, given that the scientific evidence for the utility of these approaches is still not proven it's probably best to leave them out. --Libravore (talk) 23:07, 15 April 2009 (UTC)

Calcium ion health benefits

Surely the calcium ions present in water provide health benefits to the bones and teeth, like calcium in the food? Mad.martian999 (talk) 13:45, 14 March 2008 (UTC)

I've heard that. Supposedly the hardness of the water in Kentucky (the whole state is on a huge calcium carbonate shelf) is one reason that state is famous for its horses — stronger bones. (It's also said to enhance the flavor of their Bourbon.) But this could be a myth: water hardness is measured in parts per million, meaning you'd have to drink a lot of hard water to get your MDA. More hard data is needed before we can add this tidbit. --Isaac R (talk) 18:21, 18 August 2008 (UTC)

Why do we care?

This article has lots of interesting technical details. But it doesn't explain why people care about water hardness, and spend so much money softening it. --Isaac R (talk) 18:23, 18 August 2008 (UTC)

These twe sentences can't both be right

"Hardness in water is defined as the presence of multivalent cations." "... a single-number scale does not adequately describe hardness" -> it does it's expressed for example in °f. It probably means that a classification water from (very) soft to (very) hard is not universal. —Preceding unsigned comment added by 84.196.128.79 (talk) 10:33, 20 August 2008 (UTC)

The first sentence describe a qualitative measure (i.e., it's either hard or not), the second a quantitative measure (if hard, then how hard is it). 78.22.161.214 (talk) 18:17, 28 October 2008 (UTC)

USGS information

I was interested in the number of households with hard water, so I went to the USGS site to try to find where this statistic came from and could not find it anywhere! The USGS does analysis of ground water and surface water and wells (whichever category those go in), not the water coming out of people's taps in their homes, so how could this be a USGS statistic that "households" have hard or soft water? I was hoping that someone at USGS had at least done something like multiplied the population of different areas by the type of ground/surface water prevalent in that area, but that doesn't seem to be the case. Even then you'd have to make assumptions about the prevalence of water softeners in homes. If anyone can find the primary citation for this "fact" it would improve the accuracy of this article.--Libravore (talk) 23:17, 15 April 2009 (UTC)