I was recently doing some film developing calibration runs having discovered a film densitometer I could use at work. I live in Southern California, where the tap water is frightening stuff. Having eliminated the other suspects I had begun to believe the water was causing my unusually long development times, very different than when I last calibrated my film developing back on the East Coast.

Not much on this subject was found in my books on developing and my Internet searches didn't turn up anything definite, although I admit I am not a very talented searcher. I can't recall if it was in this forum but I read a thread asking about anything that might be in tap water that could interfere with B&W film development. One of the answers came from an amateur photographer who is a chemist in the day-time. His answer was, "It depends on just how bad your water is," but gave no specifics.

It turns out that Kodak has a technical information phone number (800-242-2424, extension 19) where you actually get a human being on the phone almost immediately. He was able to tell me a number of recommended maximums for various tap water components.

The most important of these, he said, is total hardness as calcium carbonate. Kodak suggests this be in the range of 40 to 150 ppm, with 40 being the preferred end. Too high a level limits the swelling of the gelatin and leads to delayed entry of the developer.

A call to the Huntington Beach Water Dept yielded a fairly detailed analysis of the water (they check it all the time). Calcium carbonate was 161 ppm, well over the recommended upper limit. So my developing mystery may be solved.

On one of Kodak's web pages they note that good results may very well be obtained despite hard water and it was suggested to compare film developed with distilled water with that developed using tap water. I haven't had the chance to run these tests yet. I'll post numbers when I get them done if anyone's interested. (It'll be a few weeks, though.)

-- Don Karon (kc6d@arrl.net), May 01, 2002

Answers

It would be nice if Kodak publishes that (and a lot more information they are hiding) on the web.

Calcium carbonate is not very soluble in pure water at room temperature, and that high concentration leads to another question, how low is the pH of the water. If you boil the water before mixing developer, does it solve the problem? (Much of Ca++ and Mg++ ions should form salts in solid precipitation and you'll discard them. Let them settle down in a stopped bottle overnight if necessary.) if that doesn't work, try sodium triphosphate (Calgon) or Na2H2-EDTA after removing a chunk of the inorganic metals by boiling. Water boiler usually has to deal with this problem, so your hot water tap may contain less inorganic mineral components than cold tap water.

If the pH is also affected, you might have much better luck with well buffered formulae, like D-76d, XTOL or Ilford Microphen. If the low pH is due to carbonic acid or other dissolved gas, boiling should help here again, because the solubility of gas decreases as temperature goes up.

I live near Boston and have never had problem with tap water though I use activated charcoal filter for drinking and cooking.

Ryuji Suzuki JF7WEX

-- Ryuji Suzuki (jf7wex@rs.prug.or.jp), May 02, 2002.

The main reason that manufacturers don't recommend using distilled water is that they don't want to be at a competitive disadvantage with other companies. But, at about $0.70 a gallon, it's pretty silly to not use distilled water for mixing or diluting the developer solution (unless you have a very good filtering system).

-- Michael Feldman (mfeldman@qwest.net), May 02, 2002.

As a matter of interest: I see from the MSD sheets that Ilford incorporates a water softening agent, Sodium Tripolyphosphate, in all of their packaged powder developers.

As previously posted, some types of water hardness, classed as 'temporary hardness', can be removed or reduced by boiling the water.
Hardness due entirely to Carbonates falls into the category of temporary hardness.
In addition, boiling the water will remove most dissolved gases. (In fact, the removal of CO2 from water by boiling is what causes the carbonate content to be precipitated out, so reducing the hardness)
I'd be more concerned about the residual pH of the water supply, after boiling, though. Does your water authority give out this figure? If the water is acidic, then this will reduce the activity of any low alkalinity, i.e. fine grain, developer. Drinking quality water really shouldn't have a pH lower than 6, or much above 8.

-- Pete Andrews (p.l.andrews@bham.ac.uk), May 02, 2002.

I remember David Vestal writing in one of his books that, when he moved from Boston to Chicago [ I believe], he had re-do his entire developing/printing routine due to the changes in the water.

chris

-- Christian Harkness (chris.harkness@eudoramail.com), May 02, 2002.

After experiencing various problems because of minerals in tap water, I know mix all my solutions with distilled water. Also use it for final rinses of film and prints. If you pay a lot more for chemicals than for distilled water, and if you put a lot of time into your processing, why introduce a variable you can't control?

-- Jim Rock (jameswrock@aol.com), May 03, 2002.

One big problem with tap water is variation throughout the year. Chlorine & mineral content varies as does organic matter in the water. All can have an effect on your film development. Another problem crops up which bothers those without a good filtration system and that is the occasional 'flushing the lines' done by most water departments. This stirs up particulate matter, dirt, sand and all the junk that has accumulated in the lines since the last flush cycle. If you process film at this time you may end up with negatives that rival 80 grit sandpaper when dry. Distilled water is a great equalizer. It doesnt' vary with the seasons & keeps your processing at a stable starting point which leaves the mistakes to be made by you.

-- Dan Smith (shooter@brigham.net), May 03, 2002.

Here's a strange water story....

Many moons ago when I moved from central Florida (decent water) to north Florida (rather hard water) I suddenly got negs that had golfball grain, or maybe more like the size of grapefruit.

I immediately assumed that the cause was the change in water supply (it was) and mixed the developer with distilled water. _Still_ golfball grain. I mixed everything with distilled water and could still go bowling with the grain.

After a month of so of frustration, I began calling around for advice. Ed Meyers referred me to a chemist at Agfa, who said, (in a very thick German accent) "hard vater, hard vash vater, grain!"

On his advice, I had a Culligan water-softener tank installed. No more grain! Tri-X in Tallahassee looked like Plus-X in Orlando! I was astounded.

The point of all this, I suppose, is that water hardness can have a dramatic effect on neg quality, and that effect may not occur in the process step that we assume it would.

-- John Hicks (jhicks31@bellsouth.net), May 03, 2002.

I use distilled water to dilute my Minox film developer and fixer. Tap water must not be used. Extreme cleaniless is required in processing the 8x11mm frame size Minox film. Tap water will left minute deposite on the elmusion, may not be visible to the eyes, but will be visible as white spots on enlarged prints.

-- martin tai (martin.tai@capcanada.com), May 04, 2002.

So John, do you think the water hardness affected the grain through the washing process? (I assume you did the final rinse with distilled water.) That's interesting.

-- Ryuji Suzuki (rsuzuki@rs.cncdsl.com), May 04, 2002.

> do you think the water hardness affected the grain through the washing process? (I assume you did the final rinse with distilled water.)

That's exactly what happened. I wouldn't have believed it was possible, but that's the way it worked out. It never occured to me back then to try doing the wash with distilled water; I couldn't imagine it would make any difference.

-- John Hicks (jhicks31@bellsouth.net), May 04, 2002.

John, I remember your strange XTOL failure. What water did you use for mixing and diluting it? Tap water?

Just curious!

-- Ryuji Suzuki (rsuzuki@rs.cncdsl.com), May 09, 2002.

> strange XTOL failure

No, I was aware of the Xtol failures so I'd been routinely mixing the stock and working solutions with distilled water.

Which reminds me; somewhere or other, I think in an old issue of Darkroom and Creative Camera, I came across a mention that distilled water can pick up copper from copper pipes in the still. Hmmm.....

-- John Hicks (jhicks31@bellsouth.net), May 10, 2002.

Do they use sodium sulfite and ascorbate instead of corn mash and yeast these days? Maybe distilled water instead of well water through the calcium-rich blue grass soil? I don't want to imagine Wild Turkey in powder form in a yellow bag!! Nasty! (it's ok if it's liquid concentrate as long as it tastes good)

Ryuji Suzuki -- an honorary citizen of Lawrenceburg, KY (I wish).

-- Ryuji Suzuki (rsuzuki@rs.cncdsl.com), May 10, 2002.

Well if they call use coffee as a developer, why not Kentucky Bourbon. But could you bear throwing it down the drain afterwards? Giddy up TRI-X!

-- Garry D. Lewis (glewis@ftw.nrcs.usda.gov), May 10, 2002.