What kind of water to use?

In my area I buy <ozoned water> at the drug store and on the bottle it said
<equal to deminiralized water>. I'm a bit confused between ozoned, deminirilezed, distilled ... water. Is somebody can explain the differences and what is the influence on a photographic process.

deionised is ususally purest and nearest to PH7
distilled or reverse osmosis is next best
De ozoned? Just boiling it will remove chlorine and probably ozone too.
De mineralised is probably near to distilled.

Fact is that tap water is fine for all processes unless it contains a lot of minerals. The minerals don't affect the development but they do leave sediment/drying marks on the film when it dries and that is the biggest potential problem with tap water.

Therefore demineralised should be fine but many people just put their tap water through a household water filter before using it to be sure.

Off the shelf photo chemicals are buffered against PH variances in tap water so tap water is fine. It's only when you get into mixing your own chemical formulas that distilled or deionised water may be required because your home brew developer may not be buffered and may react with minerals in the water.

So for cheap more than adequate quality water, filter tap water and use for mixing developer, then final rinse of film in filtered water to be be sure of absolute minimum of drying marks on film.

No need of expensive distilled or demineralised water if you have filtered it through a household water filter.

YMMV

Incorrect

rob champagne said:

deionised is ususally purest and nearest to PH7
distilled or reverse osmosis is next best
De ozoned? Just boiling it will remove chlorine and probably ozone too.
De mineralised is probably near to distilled.

Fact is that tap water is fine for all processes unless it contains a lot of minerals. The minerals don't affect the development but they do leave sediment/drying marks on the film when it dries and that is the biggest potential problem with tap water.

Therefore demineralised should be fine but many people just put their tap water through a household water filter before using it to be sure.

Off the shelf photo chemicals are buffered against PH variances in tap water so tap water is fine. It's only when you get into mixing your own chemical formulas that distilled or deionised water may be required because your home brew developer may not be buffered and may react with minerals in the water.

So for cheap more than adequate quality water, filter tap water and use for mixing developer, then final rinse of film in filtered water to be be sure of absolute minimum of drying marks on film.

No need of expensive distilled or demineralised water if you have filtered it through a household water filter.

YMMV

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Filters do NOT take out minerals, only sediment. If your filter is part of a reverse osmosis unit, then the RO (properly maintained) does take out the minerals.

We went through this just last week, didn't we?

Bottled distilled water is so darned cheap I'm at a loss of why we keep agnozing over this. And that's speaking as a PS (Professional Skinflint.) I use it for developers and final photo-flo wash.

rob champagne said:

deionised is ususally purest and nearest to PH7
distilled or reverse osmosis is next best

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I thought it was the other way 'round???

jim appleyard said:

I thought it was the other way 'round???

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You have a dilemma then

99.999% of the water used in my darkroom is tap water (albeit through a water softener).

I use reverse osmosis filtered water for the final (PhotoFlo) rinse of negatives. And I keep a bottle of distilled water for use in diluting chemicals in alternative printing - I think I've used about 2ml in the last year, so I really wonder if the usage justifies the spaced occupied by that jug in my darkroom.

I use bottled distilled water ($0.99 for 4L) since I mix my own developers and my tap water proved to have calcium sediments. I installed a water softener in the house but cannot change my habits so I keep using distilled.

normmamiya said:

In my area I buy <ozoned water> at the drug store and on the bottle it said
<equal to deminiralized water>. I'm a bit confused between ozoned, deminirilezed, distilled ... water. Is somebody can explain the differences and what is the influence on a photographic process.

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Realy, the question is - Does it matter what water I use ?
And the standard answer is - no, not realy unless you have very poor quality tap water or a very few developers (Rodinal & such).
If you use most standard developers (D76/ID11 & similar) they are made with sufficient buffers to neutralise most tap water.
If you have well water it is worth filtering it before making up working solutions.
If it looks cloudy after mixing - then filter it again before using it.
If you have sediments in you tap water - particle filter the wash water.
It is generaly only worth using demineralised/de-ionised/distilled/reverse osmosis on the final wash & rinse - either with or without photo-flo depending on your personal choice.
Exactly what you are buying when you buy treated water is always a bit of a mistery - sellers hide behind sales speak too much
My test for this is to pour a glass of the water in question - then leave it on top of a radiator to evaporate - then judge how much sediment is left.
Idealy it would be none at all - but in reality there will always be a little.
If you have a selection of waters to choose from try them all with the same test and go with the lowest deposit that you can realy afford to use - and try it against your own tap water just for good meassure.
Good luck
Martin

It's an issue because not everywhere in the world sells gallon jugs of distilled water in their grocery stores. The only readily available product off the shelf here in the UK is deionised and that's in small 1 litre amounts usually at car stores for topping up batteries, possibly for putting in irons so they don't limescale themselves to death with our hard tapwater. I know there's a marine fish shop nearby that sells RO water and I'm probably going to get some there.
And it does matter to me, at least, if I'm mixing £16.50/25g silver nitrate plus other chemicals for van dyke brown alternative process. You do sometimes need this information though it's probably a lot less relevant to the normal B&W process unless you are mixing from scratch where no one else but you yourself is going to put it through testing like Kodak and Ilford have for their chemicals.

Deionized water

normmamiya said:

In my area I buy <ozoned water> at the drug store and on the bottle it said
<equal to deminiralized water>. I'm a bit confused between ozoned, deminirilezed, distilled ... water. Is somebody can explain the differences and what is the influence on a photographic process.

Click to expand...

The majority of dissolved impurities in modern water supplies are ions such as calcium, magnesium, sodium, chlorides, etc. The deionization process removes ions from water via filtration and ion exchange.

Resistivity/ conductivity is the most convenient method for testing Dl water quality. Deionized pure water is a poor electrical conductor, having a resistivity of 18.2 million ohm-cm (18.2 megohms).

See: http://www.myronl.com/applications/diapp.htm

Akki14 said:

It's an issue because not everywhere in the world sells gallon jugs of distilled water in their grocery stores. The only readily available product off the shelf here in the UK is deionised and that's in small 1 litre amounts usually at car stores for topping up batteries, possibly for putting in irons so they don't limescale themselves to death with our hard tapwater. I know there's a marine fish shop nearby that sells RO water and I'm probably going to get some there.
And it does matter to me, at least, if I'm mixing £16.50/25g silver nitrate plus other chemicals for van dyke brown alternative process. You do sometimes need this information though it's probably a lot less relevant to the normal B&W process unless you are mixing from scratch where no one else but you yourself is going to put it through testing like Kodak and Ilford have for their chemicals.

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Heather, my local Halfords (UK car shop) sells "Battery Water" which I use for my final rinse (without photo-flo) for about £3.50 for 5L
I am not sure whether it would meet your rather more precise water requirements or how consistent it is bottle to bottle - but it might be worth a look.
It leaves virtually no drying makes on my sheet film - which is the measure I use to ultimately determine if its suitable or not.
What I was trying to say was - for most standard B&W processes from main stream suppliers such as Ilford & Kodak the quality of the water supply is not a major issue until it comes to the final wash unless you have well water with a high mineral content.
(I agree this does not apply to the much more exacting alternative process )
Martin

Filters do NOT take out minerals, only sediment. If your filter is part of a reverse osmosis unit, then the RO (properly maintained) does take out the minerals.

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Domestic water filters can take out minerals like lime + chlorine etc. I use tap water for everything except the final wash for film, to avoid drying marks from lime from hard water depositing on the film. I find that passing the water through the filter twice gets results as good as those with distilled water.

David.

I have especially dirty tap water (small particulates), though I'm not in a very hard water area. I filter all water for particulates when making up developer, stop and fixer for films using a Paterson water filter over the tap, but never bother with distileld water as I don't have a ready source. I wash films again using filtered water then do a final rinse in distilled water but emptying the tank, letting it drip for a while then using about 300ml of distilled water, give it a really good shake, then empty, then repeat and add a little wetting agent. Before this final distilled water wash I usually had a few small drying marks, not I haven't seen one for ages. One final tip I picked up somewhere is if you are getting drying marks, when you hand the film up to dry, angle it by attaching the bottom end to a wall or something. That way, as water runs off the neg, it runs to the edge where if it leaves a drying mark it doesn't matter. If you leave it vertical, the water just runs further down the neg then dries. Since using distilled water for the final wash I've never had to do this as it leaves no mark.

I just got a dehumidifier (Singer 2100LCD) for my very wet darkroom (85% and more).
Can I use the water from the process for BW chemicals instead of the distilled water I buy?

arigram said:

I just got a dehumidifier (Singer 2100LCD) for my very wet darkroom (85% and more).
Can I use the water from the process for BW chemicals instead of the distilled water I buy?

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I've never done this myself, but have read on forums that others do; after all, it is distilled. I'd be careful about airborne dust getting in the tank as the dehumidifier sits there and does its thing.

My lab's water filtration system

Woolliscroft said:

Domestic water filters can take out minerals like lime + chlorine etc. I use tap water for everything except the final wash for film, to avoid drying marks from lime from hard water depositing on the film. I find that passing the water through the filter twice gets results as good as those with distilled water.

David.

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The Millipore filter chain in my lab (at work) does remove the ionic species from the water.

We continuously monitor the water's conductivity to insure that the water exiting the filter chain is in the 18 megaohm range.

jim appleyard said:

I've never done this myself, but have read on forums that others do; after all, it is distilled. I'd be careful about airborne dust getting in the tank as the dehumidifier sits there and does its thing.

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It has an ionizer and filter for dust and mold.

Distilled water can carry over volitile chemicals from the source into the distillate as well as mineral salts from the still, particularly the condenser head. Distilled deionized water is the purest!

An example is tap water being distilled. If it contains chlorine, that volatile chlorine can come over with the distillate and is collected. If the condenser is corroded, then salts from the corroded portions of the apparatus will also come over into the water. You might then have Ferrous and ferric chloride in the final water. Some stills used lead tubing which is even worse! I believe that lead stills are now outlawed, but were common in the 20s and 30s and were until recent times in some rural areas.

PE