Tap or distilled water for film development.

[Grandpa Ron]

I was reading Ansel's book on the negative and he recommended using distilled water for mixing developer, unless you have very pure tap water.

I had never thought of that as I live in the country and we have always had good old well water and a water softener. In retrospect, I realized that the same chemical are there, they have just been chemically modified by the softener process.

So, the question is, how important is the purity of the water and what are the effect on the negative?

 

[petrochemist]

I was reading Ansel's book on the negative and he recommended using distilled water for mixing developer, unless you have very pure tap water.

I had never thought of that as I live in the country and we have always had good old well water and a water softener. In retrospect, I realized that the same chemical are there, they have just been chemically modified by the softener process.

So, the question is, how important is the purity of the water and what are the effect on the negative?

They are not the same chemicals because they've been chemically modified. Commonly water softeners use ion exchange processes to convert insoluble calcium carbonate into a soluble carbonate or a different calcium salt - in either case the alternative being picked to be readily soluble.
I think producing calcium chloride is the usual approach, but I'm quite willing to point out my inorganic chemistry is getting a little rusty.

 

[Grandpa Ron]

Petro, Yes the ion exchange changes the compound. However, when you run a humidifier in the winter the compounds in the soften waters build a white chalky looking material on the evaporation media.

I was curious what happens in the film development process, and if the now soluble minerals in the water, simply flushes through.

 

[petrochemist]

Petro, Yes the ion exchange changes the compound. However, when you run a humidifier in the winter the compounds in the soften waters build a white chalky looking material on the evaporation media.

I was curious what happens in the film development process, and if the now soluble minerals in the water, simply flushes through.

When you run a humidifier you are evaporating away the water even soluble compounds get left behind in such exercises. It's normally only transition metal compounds that are coloured so the deposit will still be white, but they wash off much easier than limescale.

I would have thought tap water runs the risk of leaving deposits, but it will vary considerably with the tap water.

 

[jcdeboever]

I am also on well water but to be honest, I have not seen any difference at my house. I use photo flow and it works as expected. Now, a friend of mine who lives in Jackson, MI has city water and it is noticeably different compared to distilled. I have no idea why but his spots require a very saturated isopropyl micro fiber towel wipe to remove them from 135 black and white film, even with photo flow. We processed several rolls with distilled d76, distilled stop,, and distilled rapid fix, and distilled photo flow. The results were noticeably better overall so he is now doing the distilled method. I bought him some large table top containers of distilled at the water supply place near my work to reduce cost and he loves the dispensing.

 

[flyingPhoto]

I am also on well water but to be honest, I have not seen any difference at my house. I use photo flow and it works as expected. Now, a friend of mine who lives in Jackson, MI has city water and it is noticeably different compared to distilled. I have no idea why but his spots require a very saturated isopropyl micro fiber towel wipe to remove them from 135 black and white film, even with photo flow. We processed several rolls with distilled d76, distilled stop,, and distilled rapid fix, and distilled photo flow. The results were noticeably better overall so he is now doing the distilled method. I bought him some large table top containers of distilled at the water supply place near my work to reduce cost and he loves the dispensing.

Ah another michigan man. good im not all alone here.

On your friends water from detroit city. Its most likely the chlorine the city uses, and flouride.

Im in the middle of nowhere and my water is hard, if i left a capful of my well water on a plate, three days later it would be like milk stone.

The MAIN difference is the minerals. Minerals be like real shite to deal with when air drying. Used eco pro lineup for some film. magnificient quality, better then most mail labs that have done black and white film development for me.

i used distilled and "spring water" according to the bottle labels to mix everything. Very nice and clean. Dried in half the time that the well water takes. only 1 water spot where it bent over the towel it was on.

when i did my cinestill trial using well water, well it was BAD

 

[jcdeboever]

Goes to show you, you have to test and experiment. I use distilled for C41 because I am batch mixing and it's convenient.

 

[Rickbb]

Late post but my well water has too much minerals to use. Leaves weird marks and hard spots on the film. Distilled is the way to go, at least for me.

 

[Douglas Brown]

Great timing as I am returning to darkroom work after a 35 year hiatus. I live in the country using well water and salt water softener and will be mixing my chemicals up this weekend so the timing of this discussion is perfect. Now to run to the store for some distilled water.