Water for chem mix & wash: Tap, distilled or... condensation

[scheimfluger_77]

I've had a curious thought recently about water used in our darkroom activities. Having moved to mid-Missouri from drier climes, humid air bothers me but I never gave it more than a passing thought beside my comfort.

What alternatives are you using to tap water or bottled distilled water? Earlier this summer I purchased a small room size de-humidifier. I've been dumping 15-20 pints a day out the reservoir thinking, what a waste. Then it occurred to me, why not use this water for photographic purposes? It would solve the dual problem of overusing your community water supply and having to buy bottled water. Though you still pay for electricity to run the condenser on the unit. Isn't this water essentially the same as distilled except for the way it's recovered?

For that matter if you have a whole-house de-humidifying system why not run that effluent into a 25gal. tank or two to use for your darkroom? It seems like a logical plan, what am I missing?

 

[Rudeofus]

We have an electric dehumidifier in our photo club, and the container for extracted water contains some slimy deposit, most likely fungus. You do not want fungus in your emulsion, period, so check carefully before you use that water.

 

[David A. Goldfarb]

It always seems to have mildew. I wouldn't use any kind of condensate on my prints.

 

[Rick A]

Run it through a Brita or similar filter first, should be fine for all your needs including drinking.

 

[Gerald C Koch]

Commercial products like D-76 have a calcium chelating chemical in them so tap water is fine. However if you mix your own then distilled/de-ionized water should be used.

 

[scheimfluger_77]

Thank you for the feedback, it was just an idea. I might try testing this later on though.

 

[David Allen]

Here in Europe, the tap water is invariably safe to drink. However, using tap water for mixing chemicals and final wash is not advisable. Even if you live in a brand new building, the pipes supplying your property can be very old indeed! My current darkroom is in a listed building and the water needs to run for at least 20 minutes before it runs clear. For general washing, I run the water through two water filters (5 micron and carbon) but would not take the risk with film processing chemicals (I make my own).

For me the main consideration is getting consistent, clean and archival negatives. I therefore use Distilled water. At 1.99€ per 5 litres it is not expensive and, even if it was dearer, I would not risk my valuable negatives by not using distilled water.

Bests,

David.
www.dsallen.de

 

[ic-racer]

I only use filtered or distilled water for the photo-flo step. I have found the water from my dehumidifier to be too dirty for that use.