distilled water

[cheltie]

Hi everyone,
We used to have a still but have changed over to a deioniser.
The distilled water would sometimes have a PH of 6 but the deionised water I have just used has a PH of nearly 8. Is this normal? The teachers are a little confused by the readings.
Helen

[rosiegbh]

Hi, I also have a question on distilled water.
Is there an expiry date on distilled water? I make it through a still and I am now thinking I should put date on the spray bottles I make up. Is this correct? Does it deteriorate over time like the chemical solutions?

Rosemary

[Labbie]

good question, should take bets on the answer.

[Ian]

Hi, I also have a question on distilled water.
Is there an expiry date on distilled water? I make it through a still and I am now thinking I should put date on the spray bottles I make up. Is this correct? Does it deteriorate over time like the chemical solutions?

Rosemary

Surely it would depend on how sterile is the container. Biological contamination would be the only problem. The water itself should last several millennia!

Ian

[Robb]

Im very glad this subject has come up cos Im just about to order 40 L of distilled water at a cost of ninety dollars because our distilled water (previously bought) has a pH of 5.5. The chem teacher doesnt want me to use it to make up senior chemicals, is it really a problem???? Also I bought pH buffer tablets to make up some buffers to calibrate our pH probe with, will using distilled water with a pH of 5.5 affect the accuracy of the buffer or will the buffer "buffer" itself!!! Thanks heaps for any imput, I love this site Maria

Hi MariaC,

In the case here, We need to take into consideration pure chemistry here, pH will fluctuate according to town water sources and the amount of CO₂ absorbance from the atmosphere, regardless its going to happen, in some cases CO₂ absorbance will balance out pH but most cases this does not happen.

Deionised water acts as a CO₂grabber, it see's it in the air and pulls it in, like a hungry crocodile...

I have measured Modulab water which is "Pure Water" in my research days and the change in pH is within minutes. Modulab is H2O nothing else, measuring its resistance and conductivity at the same time is the only indication of its pure water state. Never open a bottle for longer than necesarry with this type of water.

In schools you will never come into contact with it, its just too expensive for the instrumentation and also cost to buy.

As far as buffers go for buffering or calibrating pH probes, only use the tablets if you have a pH probe that can be calibrated either by software or the desk top calibration and Onscreen disply. The tablet will not affect the normal workings of the probe even when the water is at pH 5 - 5.5, naturally enough the water will not be an issue for titrations. Also good argument to use is that pH is also very temperature dependant. This could also be a major contributor.

I hope this brings a good conclusion to your questions..

Cheers,

Robb.....

[Ocker]

I have a problem with teachers coming to me and complaining that our distilled water has pH of 3.5, what they don't realise is distilled water has no ions therefore it will not change the memory of the last reading, If the last reading was 7 buffer wash and take reading it will be 7, Also how clean was the test tube / Beaker they used, I can't argue with them ,they are brilliant teachers I'm just a dumb glassware washer!

[MariaC]

Thanks Robb for your reply, thats why I love this site, glad now that I haven't had the time to order the water and will just buy it as needed from the local supermarket Small fresh stocks should work fine for me.

cheers again MariaC

[vlclabbie]

I make mine up fresh from my instant deioniser that is attached permanently to the tap (vertex) and I get ph 7 and it does 2 litres in a few minutes.Its great but a little pricey .
Its well worth buying it if you have the money
Rhonda

Hi Rhonda, it's now a year on from this discussion....... but I was wondering if you could PM me the name of the product this is & the company that I can get it from? I f you can remember .... it's a while ago!

Thanks!

Cheers Kel

[agregory]

Where do you all buy your DI water from?

We have a Millipore deioniser which we need a new cartridge for. We ordered it 8 weeks ago and still not coming despite checking, ringing etc.

Having to resort to buying water.

[Ian]

I get mine from Coles in 2L bottles. Well, it is "De-ionised", actually, but it seems to work as well as Distilled! (zero conductivity, no chlorides, pH about the same as distilled, etc) and about $1.30 per 2 litres. (which is less per year than I was paying for cartridges for my Vertex filter system

cheers
Ian

[sunray18]

I buy mine in in 20L containers - and I get about 5 at a time.. and as Ocker sdaid so long ago, teachers ned to learn a little mroe about distilled water and pH!

[Ocker]

OK! Sunray
My 20L containers are old and brittle now walking past desk with a drawer slightly open and knocked a hole in bottle.
Do they supply bottles?
Do they have an exchange system?
More info please

[Labbie]

" have given up on water distillers - besides wasting water it has also been very time consuming. I now order distilled water from Refresh Waters 1300 88 32 88 and they deliver a 20 gallon container with a tap to the prep time usually within the week for $11. This lasts me quite often for ... " end of quote


This is taken from an older post, I have used this company, and so far so good.

[sunray18]

I get mine from 'Water to Go' Wyong . Delivers right to my room! $19 FOR $20l.

[mtg]

Does anyone know if there's a cheap supplier in vic. To deliver far from Melb without costing us a fortune in delivery costs?????? I waste so much water distilling, despite a fairly new still.

[RosalieM]

We bought a still from SA that someone else on here recommended. It wastes no water and is very efficient, quiet and we haven't yet replaced the filters and the water still comes out fine. Saves wasting all the packaging and me going out to get it (as far as I know there is noone in my area that will deliver water).

[smiley]

Annette, you should have a "North Qld Batteries" somewhere along Ingham Road. They're the same company up here, and I buy De-min water for 50cents a litre. It's just easier than bothering with a still, and I reckon possibly cheaper per annum that any other method. At any rate, while you're waiting for your de-ionizer, check them out.

[superbug]

Hi All,
Just wondering what everybody does for distilled water. Is it cheaper and less wasteful to buy distilled water or is it better for use to buy a new water distiller (are they more efficient these days)?

Thanks

Superbug

[Graham Kemp]

We mostly buy ours these days, with the old still kept as backup when the local shops don't have any in stock.

Not the most (cost/water) effecient way I know, but well enough for our small school's needs.

Also: Ye Olde Thread.

[Narelle01]

there are also a few threads on this topic - have a search!