Pitfalls of De-Ionized Water in Photo Solutions?

I have access to as much DI water as I wish but have never used it in photography. From some work experiences, I know that many chemical reactions rely upon free ions being available and won't function well with DI water. Does anyone out there have a working knowledge of this as it relates to typical darkroom chemistry?

The very little that I have actually read on using de-ionised / distilled water seem to be recommendations for using it, eg the instructions for Rollei ATP 1.1 DC developer specifically says you must use distilled water for all of dev/stop/rinse and wetting agent.
I've not heard anything about specifically not using it for lack of free ions (but then, I gave up chemistry after highschool), so if there are good arguments I'm all ears...

I use distilled water, which should be chemically pure water with no dissolved ions, for all my processing chemicals and it has made my work much more consistent.

I only use the de-mineralized water for the final photo-flo bath to reduce water marks.

Once you pour your developer in ion-free water you will have plenty of ions.

We used DI/DW for everything at EK in research. There is no harm in it whatsoever.

PE

Thanks, PE. We specifically avoid DI for some processes in my work as we put some viscosity improvers into suspension in water prior to adding the remaining ingredients. The material is quite specific about not using DI water for lack of free ions. I had never pursued the information as it related to photography solutions.

If it was fine with Eastman Kodak, it should be acceptable in my basement darkroom!

Only downside I know of is that it doesn't taste very good. Totally flat. For good tasting water you need certain minerals to be present. So if you ever shop for bottles drinking water be careful not to get de-ionized or distilled water.

I think most of the distilled water is actually de-ionized due to the high energy cost of converting water to steam. It requires 539 calories to change 1 gram of water at 100C to 1 gram of vapor at 100C. That's almost 7X the amount of energy needed to get the 1 gram from room temperature to the boiling point. Not very cost effective in today's economy.

I had trouble toning prints until someone (not on APUG) suggested using distilled or purified water. It worked like magic! There is something about our city's tap water that is not compatable with bleach and toners. Now I use purified water for ALL my photo chemicals. I use tap water only to wash prints.

When I worked in a lab I would fill 5 gallon containers of good 18MOhm-cm DI and bring them home for darkroom use.

Where I live the water is quite hard and full of chlorine compounds. I use DI or distilled to mix developers and fixers. A gallon of D76 in a regular 5L container without nitrogen/squeezable botthes/etc lasts for at least 9 months (longest it took me to finish it, it was a medium yellow color).
I also use it for the final wash with Ilfotol 1:200

I live between two chalk rivers and use tap water.

For making up concentrates I use de-ionised water, to mix for actual use from the concentrates I use tap water.

In Turkey final rinse is bottled water, in the UK tap water.

Ian

I've always used tap water, but the quality of it in St Paul, Minnesota is very good. I do boil it, however, to get as much air out of the water as possible before I use it. While I have used distilled water once or twice, I wasn't able to tell a difference in either longevity or performance.

I may be lucky, however, and if I move elsewhere I will of course test the water first.

Is Distilled or De-Ionized water the same as Reverse Osmosis in mixing photo solutions? Any advantage/disadvantage other than cost?

fotch said:

Is Distilled or De-Ionized water the same as Reverse Osmosis in mixing photo solutions? Any advantage/disadvantage other than cost?

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Reverse osmosis water should be OK. However it is probably more expensive than de-ionized water. It is very easy and economical to recharge a de-ionizing column. Reverse osmosis requires energy for the pumps used to make the process occur.

As Michael points out commercial developers have chelating agents in them so that tapwater is adequate. In this case, if you can drink the water it is safe to use. However, if you mix your own and don't use a chelating agent then you should use DI or DW.

We have very good tap water here, so I use that for everything routine. But for anything nitpicky I use true distilled, which doesn't cost anymore
here than deionized, which I wouldn't trust when push comes to shove (due to the nature of the companies who bottle it, among other reasons). And I use distilled w/Photoflo for final rinsing of negs, so always need it on hand anyway.

craigclu said:

I have access to as much DI water as I wish but have never used it in photography. From some work experiences, I know that many chemical reactions rely upon free ions being available and won't function well with DI water. Does anyone out there have a working knowledge of this as it relates to typical darkroom chemistry?

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Taking a pH reading in DI water is difficult That's about it. The solvent properties of water are independent of contaminate ions.

Distilled water is basically freed from what you don’t want to have in your baths: rust particles, chlorine, fluorine (yes, they poured sodium fluoride into our drinking water until 2003), algae, bacteria, sand, chalk, other debris. Not air, because there is a constant spontaneous dissolve of air in water. You make concentrates for your baths with distilled water.

Water from a synthetic resin filter is best for diluting concentrates. Towards the end of your processes you can use tap water, if you add a shot of an organic acid to the final rinse water, acetic acid or citric acid or formic acid (the best but also the most expensive).

I have prepared and used baths with tap water. There is an advantage of tap water for a developing bath, namely that the chalk binds the silver precipitate. Never forget: The light sensitive silver salts struck by light (exposure) decompose in the very instant. Silver remains in the gelatine but the now free bromine (about 80 percent of the silver salts is silver bromide) evaporates. You can smell it when you open your camera.

The evaporation of bromine continues and is boosted up in the developing bath. More silver salts are dissolved out of the film. Chalk, CaCO3, is hardly dissolved in the water. It begins to dissolve upon the presence of proton donators (acids). I mean, with the old-fashioned acid developer recipes that works. With the modern alkaline developers chalk is a nuisance. So, in general, we can use tap water for acid baths but need pure water for alkaline baths. We must ponder cost and income.

Bromine does NOT evaporate from an emulsion. The smell of film is that of the addenda (finals) put into the emulsion to preserve, stabilize and harden it.

PE

Deinonized water cannot be legally marketed in Calif as distilled. Even from the same companies, each type has to be correctly labeled as such.
On the other hand, bottled drinking water can represent all kinds of things as long as it's not toxic or otherwise contaminated. Drinking mineral water from hot springs was the fad back in the 70's. They'd add a little artificial yellow lemon or green lime flavor to it, and we'd make nasty jokes about how the color of water depended on the color of the grass which the cows ate a particular time of year.

Photo Engineer said:

Bromine does NOT evaporate from an emulsion. The smell of film is that of the addenda (finals) put into the emulsion to preserve, stabilize and harden it.

PE

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And a fine smell it is, too. I love the smell of film in the morning.

So if i can ask a dumb question, is the water from a condensing drier distilled? I mean it's years i last had a chemistry class but the process looks awfully like distillation to me

Photo Engineer said:

Bromine does NOT evaporate from an emulsion.

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Oh, my, what holds atomic bromine back then?

Gunfleet said:

So if i can ask a dumb question, is the water from a condensing drier distilled? I mean it's years i last had a chemistry class but the process looks awfully like distillation to me

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If you mean something like a dehumidifier, yes it is distilled, but the collection tank is going to have a lot of stuff like fungus, and dust. IF you want to use that, thoroughly clean the tank and empty it regularly and clean it afterwards.