Pure Water?

[John Cahill]

This the first post for a LF neophyte.
Will boiled and filtered tap water serve as well as distilled water for sensitive types of photochemistry? Or should I buy it, or get one of my country neighbors to teach me how to build a small still?

John, Mount Vernon, Virginia USA

[Bruce Watson]

This the first post for a LF neophyte.
Will boiled and filtered tap water serve as well as distilled water for sensitive types of photochemistry? Or should I buy it, or get one of my country neighbors to teach me how to build a small still?

IMHO, boiled and filtered water is insufficient. Part of what you want to do is remove the mineral content and the really small dirt. Distilling will do this where boiling and filtering will not.

You can usually buy steam distilled water by the U. S. gallon at your local supermarket. If you really want to do it yourself, there are small water distillers on the market (I think Sears used to sell a couple). You could also look into reverse osmosis processors.

I know that I saw a market improvement in my B&W processing when I moved to all distilled water. And my city water here is pretty darn good. It's just not good enough...

[lee\c]

I buy distilled gallons of water for about $.50 a gallon for mixing chems.

lee\c

[Brian Ellis]

The only use I ever had for distilled water was to rinse finished prints to reduce water spots, the water in my darkroom was very hard. I don't offhand know of any chemical process in the typical silver-based darkroom for which distilled water is needed. Some people use it to mix developers, on the theory that by doing so they can change water sources (e.g. if they move) and not have to re-test, which makes some sense especially for people who move around a lot. I've been to five different darkroom workshops and the instructors just used tap water, they didn't suggest using distilled water. I wouldn't criticize anyone for using distilled water, if it makes you feel better or if the manufacturer of some product recommends it for that product by all means do it. It isn't expensive or overly difficult but I don't think it serves any real purpose for the routine silver-based darkroom steps.

[Ron Marshall]

I find Chicago water to be fine. I only use distilled water for mixing powdered chemicals that will then be stored for some time.

[paulr]

It's good for your final soak in photo flo, to eliminate mineral spots.

I use it for developer, for good measure, but have no way of knowing if it makes a difference. It at least gives some more assurance of consistency.

And there are some formulas, like Nelson Gold Toner, that require mixing with distilled water (in this case because chlorine will kill the toner).

[ronald moravec]

Chicago water is fine. I filter thru 4 layers of Bounty towels just to be sure in addition to a commercial 3 micronfilter. Probably overkill, but I never have a problem and used to spend hours spotting prints.

[robc]

I assume you are doing black and white. Off the shelf black and white chemicals are so well buffered against acidity variations in water supply that you would need to have a seriously bad water supply to see any effect on film development and that includes chlorine which will not effect your development. However, as has been stated, water contains minerals in solution and to get rid of those so as not to cause drying spots, a final rinse with distilled or deionised water is defintely worth it.
Always use chemicals which are fresh as possible and always store solutions in air tight containers which are full.

Where you are mixing your own chemical formulas and are uncertain about the buffering of the formula then using deionised or distilled water can't harm anything and could prevent potential problems.

[John Cahill]

Thank you all for your input. I am planning to develop my first fifty sheets of film in Rodinal and I figure with such dilution I should avoid tap water.

For years I have mixed up my D-23 and D-25R replenisher (for small and medium format) using collected AC runoff water, which I filter through a chemex type coffee filter. My developer and replenisher seem to last forever with no oxidation and no problems that I have ever been able to detect.

I guess the next question would be what you all think about using filtered AC water. I know 50 cents a gallon for distilled water at the supermarket is a pittance--but you do not know how cheap I am! Come Spring, I can begin collecting AC water again, if you all think that advisable as a substitute for distilled water.

[Capocheny]

John,

Can't speak for the others but I never had a problem (back in the days when I use to develop and print my own films) with using tap water for mixing chemistry. I use to use Rodinal, Accufine, and D76.

However, when I worked for a newspaper, all of their water was run through a filtration system and the filters were changed every other day.

That said, if you had the water we've had for the last couple of weeks, you'd most likely distill AND filter the stuff! It was pretty bad due to the storms we've been experiencing. In this case... I would have said distilled water would have been the order of the day!

Cheers