[windows_chepstow]

Is there any difference?

I spoke to a customer today and explained how my pure water system worked.

She informed me that she worked in a laboratory for years and asked me to specify what I actually meant by 'pure water'.

'Er, well, er water with no impurities in it, innit?' was my reply.

'Ah', she said nodding, looking at my (David's) information sheet.  'Di ionised water'.

I didn't do chemistry at school and my O Level physics and biology doesn't cover this, although I do remember that osmosis is the passing of water from a high potential osmotic solution to a low potential osmotic solution, or something.

Anyway, what's the difference, if any between pure water, soft water and di ionised water?

[windows_chepstow]

In lay-man's terms.  If anyone starts talking about 'molecular structures' and 'atoms' and stuff; you're deleted!

[H h20]

As far as i know soft water contains less solids than hard so the tds reding will be lower,thats just my thought,Gaz.

[windows_chepstow]

As far as i know soft water contains less solids than hard so the tds reding will be lower,thats just my thought,Gaz.

So soft water is softer than hard?  (I'm being sarcastic here, sorry).

Okay then, soft water is 'fairly pure' water.  A low TDS reading.

So what's di ionised water and pure water?  What have they got in common?

[H h20]

deionized water is pure water,soft water is better to run through a di resin on it`s own,where as hard water will need an ro unit then polish it off with di resin to make it pure or deionized what ever you want to call it,Gaz

[windows_chepstow]

Gaz,

I think this sites swear filter is messing about with your link!

So you're saying there's no difference between pure water and de inonised water?

Same thing, different terms?

[H h20]

Tosh try this link,it may answer your question properly,Gaz
http://www.apswater.com/page38.html

[poles apart]

Pure water is de-ionised water also known as demineralised water. Great for windows and cars but not good for drinking, so if you're feeling thirsty when cleaning have a cuppa! Also make sure if you are making up a diy kit that you use plastic fittings as opposed to metal (unless it's stainless) as pure water will scour the pipework and remove elements into the water.
Rod

[Moderator David@stives]

or brass

[windows_chepstow]

Tosh try this link,it may answer your question properly,Gaz
http://www.apswater.com/page38.html

Thanks, Gaz, good link:

Deionization
Deionization is a method used most often by laboratories to produce purified water on-demand and is able to purify water to a maximum resistivity of 18.2 megohm/cm at 25 º.  A deionization system usually consists of from one to four cylindrical cartridges hooked up to plumbing and hanging on a wall near a sink.  While it doesn't produce absolutely pure water, it is convenient and quick, and may be sufficient for many applications.  It is an excellent system for removing dissolved solids and gases, although it has a generally poor rating for other impurities.

It works by exchanging hydrogen ions for cationic and hydroxyl ions for anionic contaminants in the feedwater. The deionization resins are tiny spherical plastic beads through which the feedwater passes.  After a while the impurities replace all of the hydrogen and hydroxyl groups in the resin, and it has to be replaced or regenerated. 

This system has some disadvantages. It requires the assistance of another system to produce absolutely pure water. Small fragments of the ion exchange resin are washed out of the system during operation, and stagnant water in the cartridges can actually encourage the growth of bacteria.  It does not remove all of the dissolved organics from the feedwater, and these can foul the ion exchange resin. It needs to be combined with other purification technologies to achieve the level of purity required for research. 

[Philip Hanson]

Distilled, de-ionised refer to the method used for purification, not the water itself.

Distilled water is water that has been boiled to a vapour and then allowed to condense again.  The dissolved impurities are all left behid in the boiling pot (this is what limescale is).  Distilled water is very pure, however, distilling water is a relatively expensive and slow process.

Rainwater is essentially "distilled" by evaporating from the sea, lakes and rivers and then condensing again as rain.  Thats why rain water is very pure, and if you could collect enough of it, would be perfectly okay for window cleaning.

De-ionised water, is water that has had the "ions" removed.  So what's an "ion"?  Ions are the dissolved solids.  For example, Salt is a compund called Soduim Chloride, literally a combination of Sodium and Chlorine.

When you dissolve salt in water, these two elements seperate into charged particles called "ions" The sodium has a + charge, the chlorine a -

Special resins remove the ions from the water, hence the term "de-ionised" water.

(Technically, they don't actually 'remove' the ions, but they exchange them for H⁺ and OH^- ions.  These, being oppositely charged are attracted and then combine to form H₂O.  Or water, of course!)

-Philip

[Davindo Cleana]

I thought it was - in this order:

tap water = hard or soft
pure water = filtered through ro
deionised = through the resin

so the finished product cant be simply pure, otherwise we would be able to drink it wouldn't we

[rosskesava]

Interesting thread.

The point about pure or de-ionised water not being fit for drinking?

I cannot see why pure water is not the best water to drink? I'm probably wrong though. I'm now curious.

Cheers

[dai]

Well if tap water is fit for drinking, and DI water isn't then the resin must either contain something, or change the chemical make up of the water in some way. The mere removal of desolved solids would not make it unfit for drinking.
Is it true that DI water can't conduct electricity and thats how TDS meters work? DAI

[ian davison]

Resin is charged using  caustic & acid so bearing that in mind i wouldnt drink it if i were you!

 

[rosskesava]

But if the water is 100% pure with 000 TDS doesn't that mean H20 and nothing else?

I've been searching the net but as yet I can't find any thing specific.

Cheers

[dai]

This is the answer I got, "can you drink deionised water.
Yes, But it is not advisable.   Deionized water is water that has
undergone filtration and removal of specific minerals.  Depending on the
system, deionized water although purer in mineral content may contain
higher levels of microorganisms.  This is due to the fact that residual
clorine which is added to many water systems is removed in the deionizing
process.

[Solo Cleaning]

 Deionized water is water that has
undergone filtration and removal of specific minerals. 

The body requires certain minerals to survive. Often these minerals are absorbed from the water we drink. As an example of this in certain parts of Scotland there is a high rate of heart disease due to the low amount of zinc found in the tap water. So though a glass of di water will not kill you in the long run it will not benefit your body
Lee

[Dominic]

As solo cleaning said I think that pure water can take the good stuff out of you just like it attracts the dirt off your windows.

Dom

[callum macleod]

or brass

hi just curious here is having brass fittings a problem with pure water will it contaminate the purity?