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

[bernard_L]

I use since a number of years de-ionized water for mixing film developer and for the last rinse (photo-flo) of negatives. Last week went to the hardware store to re-stock a pair of 5-litre jugs. The new labeling caught my eye.

• Not suitable for drinking; OK, everybody needs minerals supplied by drinking water, so I understand that de-ionized water is not for drinking.
  
• In case of ingestion, keep this label and call the poison treatment emergency number... Uh-Ho! reading further:
• Contains E301 Sodium Ascorbate (does not sound poisonous) and E310 Propyl Gallate. Hmm, food additives can't be that poisonous?

Anyway, It never crossed my mind to drink any of that de-ionized water. BUT, I thought it was de-ionized (ion-free, except from inevitable H+ and OH-), like the de-ionized water used in microelectronics laboratories. So:
Question to experts in photographic chemistry:

• Could the listed ingredients have an impact on as-mixed developer properties?
• Same question for possible un-listed ions resulting from the ion-exchange fabrication process
• Would it be equally acceptable to use tap water, filtered to 5-micron size, for the two uses listed above?
  
• Should I worry about the pH of my tap water, and above what level would it be objectionable?
• Does Photo-Flo (and similar products) besides decreasing surface tension, contain ingredients to "hide" carbonates or other such minerals conducive to drying marks?

Thank you

 

[Fritzthecat]

I have no idea what E310 Propyl Gallate would be used for, especially in water. E301 Sodium Ascorbate is basically ascorbic acid, vitamin C, a food preservative. Again, I see no reason it would be needed in water. Is the label just precautionary in case there is some in it? I use steam distilled water to mix chemicals to stock solution, then usually tap water for final working solution. I do have a whole house particulate filter on my water line, we also use a Zero Water filter pitcher for making coffee and tea, there are times when our water smells of chlorine.

 

[Ponysoldier]

I always used distilled water for mixing chemicals but never de-ionized... worked for years in the medical device manufacturing field and the resin-bed de-ionizing filters put me off the thought of using DI water instead of distilled. There were always numerous cautions about washing ones' hands after DI water contact. I realize this is all anecdotal but I don't see any benefit in de-ionized. Maybe ignorance is bliss!
Joel

 

[JensH]

Hi,

I don't think "destilled" water from common stores is ever destilled. Ion exchange columns are used.
Even the best "triple-destilled" water we hat at university (analytical chemistry department) was de-ionized, just by a better column.
Anyway, I don't want any additivs in it and as little metal ions as possible.

Best
Jens

 

[Tobes71]

All photographic chemicals are designed to be made up with tap water. Imagine the cost if you were running a busy photolab and were getting through hundreds of litres of distilled water every day? I use tap water and just add photo flow the final wash. I have zero problems and I live in a very hard water area (chalk hills). Use tap water, or if you are feeling fancy get a britta water filter. I used to use de-ionsed water but haven't seen any difference since stopping.

 

[RPC]

I don't bother with distilled or de-ionized water when mixing pre-packaged chemistry, but I always use distilled water when mixing chemistry, especially developers, from formulas. I have had problems using tap water, but never distilled water.

 

[Svenedin]

I live in a very hard water area. I had problems with drying marks on film so switched to deionised water for final rinse (but not mixing of chemicals or wash). I don't know where I could buy distilled water but deionised is sold for topping up car batteries and seems fine. I use my very hard tap water for processing prints without issue.

 

[mshchem]

I live in US Midwest. The bed rock here is composed of nearly pure Calcium Carbonate. Hard water is an issue. Some cities treat the water to produce excellent moderately hard water that works great. Where I live I use a reverse osmosis system for drinking water and for my photochemistry. We have a water softener that converts the calcium carbonate to sodium carbonate for bathing and general use. The levels of sodium carbonate are so high it just wont work for making powdered developers like Kodak XTOL.

I worked in labs for years where we had deionizing systems. There was nothing toxic about it. Most tap water can be made palatable by simple filtration through a carbon block filter.

 

[MattKing]

I just mixed some X-Tol using water labelled to indicate it was "steam distilled" and had been subject to "ozonization". $1.99 plus deposit and tax for four litres at London Drugs.
I wanted to make sure the iron content was low.

 

[Gerald C Koch]

You can remove the temporary hardness from tap water by boiling it for 5 minutes. Allow it to stand over night and decante the clear portion. You can also filter it. Cheaper than buying bottled water.

 

[iandvaag]

+1 to what Gerald said.

Drive off CO2 by heating; the HCO3- ions in the water are converted to CO32- by LeChatelier's principle, which causes the Mg2+ and Ca2+ precipitate out as carbonate salts. It's a pretty clever trick.

 

[RalphLambrecht]

All photographic chemicals are designed to be made up with tap water. Imagine the cost if you were running a busy photolab and were getting through hundreds of litres of distilled water every day? I use tap water and just add photo flow the final wash. I have zero problems and I live in a very hard water area (chalk hills). Use tap water, or if you are feeling fancy get a britta water filter. I used to use de-ionsed water but haven't seen any difference since stopping.

same here. I always used tapster wherever I lived(Michigan and FL,US,UK and Germany);there is no need for distilled water unlessrhatever comes out of your tap smells awful.

 

[bernard_L]

Thank you all for the informative answers. Two extra bits from my side: (a) here in France "steam-distilled" water is not found on store shelves; (b) half of the reason for my buying "de-ionized" water was to guarantee the absence of particles and calcium carbonate in the final rinse of negatives.
More.

I use my very hard tap water for processing prints without issue.

Agreed, same for me (moderately hard water). The issue of (whatever) water arises only for neg dev and final rinse.

We have a water softener that converts the calcium carbonate to sodium carbonate for bathing and general use. The levels of sodium carbonate are so high it just wont work for making powdered developers like Kodak XTOL.

Indeed, we don't want to mess up the dev formula with extra sodium carbonate. And, possibly the commercial "de-ionized" water also exchanged calcium ions to sodium ions; except it is not required to list that in the MSDS. So my take from your statement would be: filtered tap water for dev mixing, and "de-ionized" water for final rinse?

You can remove the temporary hardness from tap water by boiling it for 5 minutes. Allow it to stand over night and decante the clear portion. You can also filter it.

Nice trick. But not a small job when mixing a 5-litre pack of D-76.

I don't bother with distilled or de-ionized water when mixing pre-packaged chemistry, but I always use distilled water when mixing chemistry, especially developers, from formulas.

Why that distinction? For instance Kodak's D-76 versus home-cooked D-76D (the one with 8g borax+8g boric acid)?
Is it because the commercial powder contains Calgon or similar to mitigate calcium carbonate. Other reason?

I confess I did not do my homework properly, and just now under "Similar threads" found this:
https://www.photrio.com/forum/threads/pitfalls-of-de-ionized-water-in-photo-solutions.118423/
which actually does not help as there are statements in all directions.

Bottom line. Measure pH of tap water. Install particle filter. Stay with "de-ionized" water for final rinse until tests with non-critical films show that the particle filter does its job and equals the performance of "de-ionized" water as a clean final rinse.

 

[halfaman]

My mother has a distilled water equipment like this for ironing

It is a heater chamber at the bottom made of a stainless steel beaker heated electrically with a condenser on top and a carbon filter on the tap. It takes 3-4 hours to make 4 liters of REAL distilled water out of 20 liters of tap water. I "steal" some just for final rinse in B&W (wetting agent) and color (stabilizer) processes.

I have found websites in Spain and UK, I suppose will be available in other european countries.

 

[Doremus Scudder]

There are a couple of reasons to use distilled/de-ionized water for photo purposes.

Mixing saturated solutions of stock chemicals is best done with distilled water. Example: Stock Solution B for PMK is a saturated solution of sodium metaborate. If you mix that with tap water it will not all go into solution, leaving lots of precipitate, more the harder the water is.

If your tap water is hard enough to leave mineral deposits on your film after drying, you need a distilled water final rinse, and not just the 30 seconds in Photo Flo. Yes, you can combine this step with the wetting agent, but you need to let the film soak for long enough to affect enough leaching out of the minerals in the emulsion to prevent the marks. Exact time depends on the hardness and mineral content of your water.

For mixing working solutions, tap water generally works well. However, I have noticed a slight difference in developer activity with working solutions mixed with very hard water compared to those mixed with softer tap water. I used to have a 10% difference in developing times between my residences in the U.S. and Europe to get the same results.

I don't know about the chemical content of de-ionized water, but the original post is a bit troubling and I'm curious. Just what are the methods used for de-ionizing water and what are the residual chemicals left behind in the water? And, why the caveat about not drinking de-ionized water?

Best,

Doremus

 

[Ces1um]

My mother has a distilled water equipment like this for ironing

It is a heater chamber at the bottom made of a stainless steel beaker heated electrically with a condenser on top and a carbon filter on the tap. It takes 3-4 hours to make 4 liters of REAL distilled water out of 20 liters of tap water. I "steal" some just for final rinse in B&W (wetting agent) and color (stabilizer) processes.

I have found websites in Spain and UK, I suppose will be available in other european countries.

We used to use one of these at my dental office for years, until one day it caught fire. Now we buy the stuff pre-made. When it was working though it worked well.

 

[pentaxuser]

I live in a very hard water area. I had problems with drying marks on film so switched to deionised water for final rinse (but not mixing of chemicals or wash). I don't know where I could buy distilled water but deionised is sold for topping up car batteries and seems fine.

I have just checked your picture. I have just realised that the de-ionised water may have changed your appearance slightly over time but may, on the other hand, have improved your taste for marrow bones?

We may need to keep this thread on a slightly whimsical note

pentaxuser

 

[destroya]

My mother has a distilled water equipment like this for ironing

.

i have a similar unit that i got new for a great price. I use it (the water) to mix all developer stock solutions, fixer as well as for photo-flo and never had any issues after. for everything else, tap water is fine. but i do use britta filtered water to mix up the developer when a stock solution is not used. its easy to keep a 2 liter filter at room temp.

 

[Svenedin]

I have just checked your picture. I have just realised that the de-ionised water may have changed your appearance slightly over time but may, on the other hand, have improved your taste for marrow bones?

We may need to keep this thread on a slightly whimsical note

pentaxuser

I don’t drink it and neither does the dog! It has however stopped drying marks on negatives. It needs more than just a final quick rinse with a few drops of mirasol but a 10 final soak seems to do the trick.

 

[lantau]

And, why the caveat about not drinking de-ionized water?

It's probably not produced and monitored as required by drinking water regs. It's a technical water. That's why they print the warning. And those ion exchange resins may well be microbiologically contaminated. For technical use they don't need to care as much.

 

[RPC]

Is it because the commercial powder contains Calgon or similar to mitigate calcium carbonate.

Yes. Pre-packaged chemistry generally contains ingredients which protect it from such gremlins in the tap water. If a formula being mixed does not call for those ingredients, which is usually the case, then distilled water is strongly advised.

 

[Andrew O'Neill]

All photographic chemicals are designed to be made up with tap water. Imagine the cost if you were running a busy photolab and were getting through hundreds of litres of distilled water every day? I use tap water and just add photo flow the final wash. I have zero problems and I live in a very hard water area (chalk hills). Use tap water, or if you are feeling fancy get a britta water filter. I used to use de-ionsed water but haven't seen any difference since stopping.

I always use distilled water to make up stock solutions. Tap water for further dilutions.

 

[Wallendo]

I use distilled water available at most grocery stores for less than $1 for a US gallon. I usually use this for making stock solutions and a final rinse with tap water for the rest of the process. It is also available in drug stores, but they usually charge a little over $1/gallon.

The main use for these products is use in humidifiers, CPAP machines and nasal irrigators. The rarity and cost of this product in Europe amazes me.

 

[cramej]

It's probably not produced and monitored as required by drinking water regs. It's a technical water. That's why they print the warning. And those ion exchange resins may well be microbiologically contaminated. For technical use they don't need to care as much.

Apparently, deionized water can contain bacteria and viruses since it is not 'filtered' like tap or has been distilled.

 

[mshchem]

Obviously different countries regions have different standards. "Pure" water will grow all sorts of things. Decades ago, before RO and fancy deionizing equipment was available, I visited a lab that used clear Vinyl tubing to distribute properly distilled water in the lab. Green algae was everywhere in the tubing. The testing they did was for calcium, phosphorus, magnesium etc. The algae didn't matter.

If you want to find out what kind of dissolved solid content is in your water, take a half a liter and gently boil to dryness. Properly deionized, demineralized, or distilled water should leave practically no residue.

I use a 5 stage reverse osmosis system. 4 of the 5 stages are for sediment, granular activated charcoal for organics and chlorine, a carbon block filter at the last step for "polishing" the taste. The real magic happens at the RO membrane. These systems use a lot of water, probably takes 4 liters to make 1 liter. I get close to 1 million ohm per cm water, ( measured by two 1 cm sq electrodes, 1 cm apart) The internet experts tell me that absolutely pure water is 18 M ohms.

I had a humidifier to boil water and add steam to the air. Two electrodes in water plugged into 120 VAC 60 Hz. It worked great with my softened tap water, my RO wouldn't conduct electricity, had to add a tiny pinch of salt to get the conductivity high enough to boil the water.