De-ionized water: actual content, suitability for phto use.

[Old_Dick]

Decades ago, I was reading an article about using distilled water. It It might have been AA who was having some problems developing film, he was using tap water. Called the city water department and asked about the water quality. "Our water is the best, we are always testing". The only thing we do is add is a little mild acid to the supply to clear the lines. Here is a interesting link.https://www.thoughtco.com/distilled-versus-deionized-water-609435

 

[mshchem]

Decades ago, I was reading an article about using distilled water. It It might have been AA who was having some problems developing film, he was using tap water. Called the city water department and asked about the water quality. "Our water is the best, we are always testing". The only thing we do is add is a little mild acid to the supply to clear the lines. Here is a interesting link.https://www.thoughtco.com/distilled-versus-deionized-water-609435

This Is a GREAT article. RO is a good compromise for darkroom use. In the US most "purified" bottled water is produced using RO and carbon filtration. DI water works great in a lab, but as is noted in this article it can react with metals. DI in chillers can corrode aluminum etc.
Rain water would be a darn good low cost source for pretty mineral free water, especially since natural gas has displaced coal in North America. The rain no longer contains sulfuric acid.

 

[craigclu]

I brought this up a few years back and it generated this thread:

https://www.photrio.com/forum/threads/pitfalls-of-de-ionized-water-in-photo-solutions.118423/

 

[AgX]

• Contains E301 Sodium Ascorbate (does not sound poisonous) and E310 Propyl Gallate. Hmm, food additives can't be that poisonous?

First I thought the latter was a repellant to keep people drinking that technical water, but it isn't.
As the Ascorbate it is a food preservative (though a questinable one).

In such technical water I would not want either of them.