View Full Version : Optimal water quality

Peter Hruby
25-Jan-2006, 09:17
I am just wondering what is optimal water conditions for photography? Hard, soft, in between and what kind of filter you using to purify water and why, if you can mention product manufacturer it would be great.

I am looking for good filtration system (does not decrasing water presure too much) which consists one filter can and can be atached to pipes.


David Beal
25-Jan-2006, 09:30
Peter, I use distilled water for developers (available locally at 2 x 1 gal. jugs for 99 cents), and filtered tap water for everything else. (Depending on the pH of the filtered water, you could use that for developer, I suppose).

The filter I have is a standard home water purifier, in the cold water line. It's made by GE, but many manufacturers have the same thing.

I haven't noticed any debris on my negatives or prints, so I guess this setup works.

Good shooting.

/s/ David Beal

Memories Preserved Photography, LLC

25-Jan-2006, 09:40
Like David, I use distilled water for film developing, and also for a final wash and with the photoflo treatment. Otherwise I just use tapwater run through a BRITA filter screwed onto my darkroom spiget. That's for B&W -- for color I use distilled water for all chemical processes.

Bruce Watson
25-Jan-2006, 10:27
And I'm using distilled water for everything. IOW, steam distilled water is the only water that touches my film or the film side of my processing equipment. I'm using a Jobo CPP-2 with a 3010 tank, and can process 10 sheets of 5x4 using about six liters of distilled water. The distilled water costs me about $0.15 USD per sheet. That's mixing chemicals, dilutions at processing time, washing, final photoflow rinse, and cleanup - all of it.

Even if you are willing to pay the cost of the plumbing and the filters, the payoff is often years away. That, and the smallest readily available filters are 5 micron. If you do more than 10x enlargements and you have particles in your water that are just under 5 micron, you are likely going to see those spots in your final prints. Also, the filters don't help you with plumbing deposits between the filters and your faucet.

So, to answer your question: what is optimal water conditions for photography? I would have to say it's completely pure H2O, and steam distilled is the best and most cost effective way to get it.

neil poulsen
25-Jan-2006, 10:32
The area in which I live has just about the softest water anywhere. 'Course, we got a lotta rain, too! So, softer isn't necessarily better for photography.

Chemically speaking though, I would think the fewer minerals the better. (Just an opinion.)

I use filtered tap water for all mixing, including developer. I don't filter for print washing. I should probably consider whether to use distilled water for developer and final wash.

25-Jan-2006, 11:06
one of the biggest issues--and mysteries-- is how water quality influences washing time for fiber based prints. optimal wash times can range from 30 minutes to 4 hours or more. which is why it's important to test for residual thiosulfate (and retest any time you move).

last i read, no one understood what factors were responsible for differences, so i haven't seen any generalizations like "hard water is better" or "calcium is good, iron is bad." someone might figure it out one day. in the mean time all you can do is test.

i use distilled for film developer final rinse (with photo flow), and certain toners. tap for everything else.

25-Jan-2006, 11:09
I have a Kinetico plus GX deluxe system. It's a reverse osmosis system with a 20 gal. holding tank. I had them run A goose neck faucet to my darkroom sink as well as upstairs into the kitchen sink and ice maker. My city water tests at about 250 ppm. The ro system tests at 0-ppm just like a jug of distilled water tests at. It purifies at about a gallon an hour. I use the ro water for everything but mixing my metal salts. And it would probably be ok for that too but it is such a minute amount of water that I just use distilled instead. It comes in so handy, especially since I'm doing ULF and I'm using more volume. No more lugging 20 gallons of water from the store then downstairs. I use it for all my pyro developing and all my clearing baths and it works like a charm. Total costs I think was around 1200.00 installed with two faucets, the large holding tank and connection to the ice maker. Plus it tastes great. When your using 20x24 trays with over a gallon of water per clearing bath and 3000ml of developer at a time, plus presoak, stop and fix it will pay for itself in no time. Then again I do a lot of printing. It's one of the wisest investments I've made for the darkroom.

25-Jan-2006, 14:30
for B+W processing the biggest problem is mineral content of water which leaves sediment when the film dries. B+W chemicals are more than sufficiently well buffered to stop problems due to acidity or alkalinity (read pH) of water. However, for a consistently clean supply then one of these dionisation units are cheap and simple to install. Just include a water shutoff tap on the inlet side so that you can easily change the cartridges as necessary. There are other more expensive units at the site but I think the one at the link below is more than adequate for film processing.

deionization unit (http://www.coleparmer.com/catalog/product_view.asp?sku=0150320)

incidentally water (H2O) is what is called an amphiprotic substance and that it reacts with itself. ie H2O + H2O gives H3O+(aq) and OH-

'pH' is in fact a measure of the Hydrogen Ion concentration and stands for power of Hydrogen ionisation.

So if you go and buy deionised water it will not remain at the same level of deionisation. It will reach a state of equilibrium but won't be as deionised as freshly deionised water. So there!

Conrad Hoffman
25-Jan-2006, 15:47
I remember seeing a Kodak recommendation for hardness to be between two specific values, not too hard, not too soft. IMO, most people have water that's on the hard side, prone to leaving spots. Since hardly anybody knows their water hardness, and it may change during the year, distilled or R0 water is a surer bet. My water comes from a nearby lake, is not too hard and not too soft, so I just filter it.

Ed Richards
25-Jan-2006, 16:06
Look hard at your commerical distilled water. Unless your state regulates bottled water, there is no control over what is in the bottle, no matter what it says on the label. I suppose if you were curious, you could just boil down a gallon and see if there was anything left.:-)

25-Jan-2006, 16:27
"for B+W processing the biggest problem is mineral content of water which leaves sediment when the film dries"

chlorine can be another problem. some formulas, like nelson gold toner, are killed by it.

25-Jan-2006, 16:40
"chlorine can be another problem. some formulas, like nelson gold toner, are killed by it"

for film development chlorine content should not normally cause a problem. But I think gold toner uses Gold chloride so yes, there could be an effect there but I have never experimented with that.

Boiling water for 3 minutes or so should drive off any chlorine content.

Whether distilling would recondense the chlorine or not I'm not sure. It may depend on whether you are using a closed system or not.

Henry Ambrose
25-Jan-2006, 17:05
I've seen RO filters "on sale" recently at home centers. They are selling for under $200 and typically make about 10 gallons per day. I've had one for several years and am very pleased with it.

26-Jan-2006, 12:37
"But I think gold toner uses Gold chloride so yes, there could be an effect there "

yeah, it probably is the gold chloride. mixing nelson gold with tap water will give you toner than lasts just a couple of uses. i agree that chlorine doesn't seem to effect most other things. just bringing it up to point out that different chemicals cause problems with different processes.