Green Building Forum - Hard and soft water

Hard and soft water

tony — Mon, 04 May 2015 16:21:10 +0100

I have a few comments on the recent piece in GBM with the above title.

In the first paragraph it sounds like "most people fit water softener" this was not the intention nor it it the case, domestic atersofteners are a very much a minority sport.

I cannot believe that we are talking about centralised softening as a good thing. It would never be allowed nor would it happen, there would be a public outcry against it, protests in the street. All our water supplies are of very high quality. Centralised water softening is bad for humans especially those with any kind of heart condition and also soft or softened water is bad for teeth and bones, a fact not mentioned. Further softened water can more easily leach heavy metals contained in older systems, not mentioned either.

To try to argue from the point of view of energy efficiency is not a bright place to come from. The hugely vast majority of heat exchangers in boiler work on a closed system where there is no hope of depositing scale due to the small volume of water involved. In the case of hot water heat exchangers, typical in combination boilers where would the heat go that does not go into the hot water? we talking about a 7.5% loss of heat transfer efficiency this is different from or a 7.5% loss in fuel efficiency, But it sounds like it is. What happens to the heat that goes into a scaled up immersion heater element with 10mm of scale on it? Answer, it goes into the water in the cylinder.

The explanations of hard water and how ion exchange resins work miss a little of the science.

Bottom line for me is I hope that the UK does not follow suit, I would not like to see central softening of water

Hard and soft water

skyewright — Mon, 04 May 2015 17:19:29 +0100

Posted By: tonyI cannot believe that we are talking about centralised softening as a good thing. It would never be allowed nor would it happen, there would be a public outcry against it, protests in the street.

Over 30 years ago (so my memory may be a bit off), as a Civ Eng student at Leeds Uni, we went on a visit to a water extraction plant over towards York. They were extracting water from a hard water river source (the Ouse) & pumping it it to Sheffield. The Sheffield area is used to soft water, so the water was being treated in huge tanks (using Alum?) before pumping.

Long time ago, maybe things have changed?

Hard and soft water

fostertom — Tue, 05 May 2015 15:57:37 +0100

Posted By: skyewrightthe water was being treated in huge tanks (using Alum?)

Isn't that what caused that huge water works mistake in Cornwall that caused widespread health/Alzheimers consequences, tho the govt continues to dispute/refuse compensation?

Hard and soft water

SteamyTea — Tue, 05 May 2015 16:15:45 +0100

This one.
https://en.wikipedia.org/wiki/Camelford_water_pollution_incident

Hard and soft water

billt — Tue, 05 May 2015 16:16:09 +0100

Alum seems to be used as a coagulant (to remove small particles) rather than a softener.

I rather doubt than softening is used on any public water supply. No benefits, expensive and possible health issues with salt based ion exchange or phosphate dosing.

Hard and soft water

SteamyTea — Tue, 05 May 2015 16:18:17 +0100

Does reverse osmosis soften water, I seem to remember that they were going to do with in London.

Never had trouble with hard water since I moved from Buckinghamshire.

Hard and soft water

tony — Tue, 05 May 2015 16:34:14 +0100

reverse osmosis will de-mineralise water, take out all the ionic compounds, including hardness

Hard and soft water

fostertom — Tue, 05 May 2015 16:58:20 +0100

Potable water's supposed to be loaded with minerals (as is rain). Otherwise you might as well drink distilled water - completely dead, not a nutrient, in fact becoming a poison. And the more solutes you remove (by distillation or reverse osmosis), the more agressive the water becomes as a solvent. Rotten idea.

Hard and soft water

skyewright — Tue, 05 May 2015 17:12:23 +0100

Posted By: billtAlum seems to be used as a coagulant (to remove small particles) rather than a softener.

Yes, it was certainly acting as a coagulant (you could see the clouding in the water).

Since yesterday I remembered the name of the treatment works, Elvington. That just led me to:

http://www.bbc.co.uk/history/domesday/dblock/GB-468000-447000/page/9

Which confirms the use of "chemicals" to "change the colour and to get rid of bacteria", and the destination as South Yorkshire. The river is the Derwent, rather than the Ouse. No mention of soft/hard, but S Yorkshire tap water is certainly soft & Sheffield residents would be upset if their kettles suddenly started to fur up. I'm pretty sure the Darwent flows through limestone country.

Edit to add: Just did another search & found this (Sheffield people complaining about furred up kettles...):

http://www.sheffieldforum.co.uk/showthread.php?t=651374

Hard and soft water

Peter_in_Hungary — Tue, 05 May 2015 17:51:17 +0100

Posted By: tonyWhat happens to the heat that goes into a scaled up immersion heater element with 10mm of scale on it? Answer, it goes into the water in the cylinder.

Yes, but the element runs hotter. When I was running an immersion heater it would last about 5 years before burning out. I would then unbolt the base plate with about 4" of scale around the element, bin the whole lot and replace it (20GBP and a couple of hours). You could extend the 5 years by running the DHW at 60 rather than 80.

Hard and soft water

jamesingram — Wed, 06 May 2015 08:38:19 +0100

Been told by Gas engineers not to put (salt) softened in sealed systems on condensing boilers as it bad for the heat exchange. If I fill systems I use the bypass whilst doing it.

Hard and soft water

andyman99 — Wed, 06 May 2015 10:17:14 +0100

Posted By: fostertomPotable water's supposed to be loaded with minerals (as is rain). ....

I thought rain water was low in minerals? Last time I filled my CH system I used rain water to try and stop the popping sound from my boiler (non condensing). I had tried all sorts of chemicals, but rain water seemed to do the trick.

Hard and soft water

SteamyTea — Wed, 06 May 2015 10:27:04 +0100

Tommy has the minerals
https://www.youtube.com/watch?v=c8Fi08u8bh8

Hard and soft water

tony — Wed, 06 May 2015 10:44:05 +0100

Artificially softened water will kill aluminium heat exchangers but is ok with iron, steel and stainless.

Hard and soft water

RobL — Wed, 06 May 2015 10:52:32 +0100

Cambridge water is 320ppm (mg parts CaCO3 per Kg water) - which is described as 'hard'.
We had a test kit for our freshwater fish years ago - and rainwater from our barrel here was < 20ppm, so we tended to use that.
My fave fish was the newt, he used to climb out of the tank and get all over the place. Got halfway up Mrs Robl's leg one day, she was a bit shocked. The shark got him in the end though.

Hard and soft water

fostertom — Wed, 06 May 2015 12:34:34 +0100

Hm, well gardeners know that a bit of direct rain is worth 3x as much tap water, and is even better than water from the rainwater butt. That, they say, is because of all the minerals (perhaps they mean 'trace elements') the rain picks up from the atmosphere. So maybe not high concentration, just variety and quality? Also good for humans - next time it's raining keep your mouth open!

Hard and soft water

Peter_in_Hungary — Wed, 06 May 2015 12:56:34 +0100

Posted By: fostertomnext time it's raining keep your mouth open!

But what will the acid do to your teeth.........even if you have your good set in!

Hard and soft water

Paul in Montreal — Wed, 06 May 2015 14:12:43 +0100

Posted By: fostertomHm, well gardeners know that a bit of direct rain is worth 3x as much tap water, and is even better than water from the rainwater butt. That, they say, is because of all the minerals (perhaps they mean 'trace elements') the rain picks up from the atmosphere. So maybe not high concentration, just variety and quality? Also good for humans - next time it's raining keep your mouth open!

Rain water picks up nitrogen in the form of nitrates which are formed via lightning making NOx - there are maybe some metal ions picked up from dust in the air, but really not much. Rain water is definitely not "hard", though there will be tiny amounts of carbonic acid from the CO2 in the air.

Paul in Montreal.

Hard and soft water

fostertom — Wed, 06 May 2015 14:37:16 +0100

Ah it's the nitrates then - plus traces of many good things too I'm sure, incl 'homeopathic' imprints (take cover!).

Hard and soft water

SteamyTea — Wed, 06 May 2015 14:43:37 +0100

Posted By: fostertomtake cover!

Funny how water remembers the 'good things' but not all the bad things it comes across!

Hard and soft water

fostertom — Wed, 06 May 2015 14:58:12 +0100

That's homeopathy for you - only those signals whose harmonics resonate with the input/output/feedback circuitry of an auto-stable (but temporarily discombobulated) system (e.g. an immune system), are read with meaning hence 'reminder' effect - the rest are just noise.

Remember we're talking about ultra-weak signals, which are only readable when and if amplified by resonance with some existing circuit. We're not talking about chemical doses large enough to have any chemical effect, for better or worse.

Hard and soft water

SteamyTea — Wed, 06 May 2015 15:53:10 +0100

I shall start divining for homoeopathic water in the zero point quantum energy vibrations right this instant

Hard and soft water

fostertom — Wed, 06 May 2015 17:17:44 +0100

Oh no, it's too dangerous

Hard and soft water

rhamdu — Wed, 06 May 2015 19:05:32 +0100

Gardeners like rainwater because (1) it's free (2) it's better for those plants which don't like calcium and prefer acid soils. There are quite a lot of these, including many plants which naturally grow on peat bogs or up in trees.

The nitrogen content of rainwater is enough to support wild ecosystems but won't deliver the kind of lush growth that gardeners and farmers expect. Here in Brighton I suspect gull poo is a more important nitrogen source than rain.

Hard and soft water

Simon Still — Wed, 06 May 2015 22:42:55 +0100

Rhamdu - are you *sure* it's not magic woo? really?

Hard and soft water

rhamdu — Thu, 07 May 2015 17:54:03 +0100

I guess you all know the story about Niels Bohr?

A student visiting the great physicist's home noticed a horseshoe over the door. "Surely you don't believe in that, Professor?"

Bohr replied, "they say it works even if you don't believe in it".

Hard and soft water

SteamyTea — Thu, 07 May 2015 18:29:45 +0100

Some of the best quotes are from scientists.