Water wise washing.

[Kirk Gittings]

Looking down the road........Water here gets increasingly expensive and will only get worse. They get us to conserve and then hit us with a rate hike because revenues are down. It happens like clockwork.

I vaguely remember some water issue some years ago in England? And if I remember correctly Ilford came out with some water conservation guidelines that included something like intermittent water flow for print washing as "washing" was actually a leaching process and didn't require a constant flow of clean water.

Anyone remember this or have some insight.

[Ken Lee]

I never use running water, just osmosis. See Dishrack Film Washer (http://www.kenleegallery.com/html/tech/dishrack.php).

[Kirk Gittings]

You da man Ken! Question on prints though which are a bit more difficult to wash. Any guidelines on water changes? I am thinking of hooking up a yard sprinkler timer or such.

[Mark Sawyer]

For negatives and glass plates, I run them through a series of water-baths in cereal containers like the type in the attached photo. They come in three sizes (4x5, 5x7, and 8x10! :) ). The local Family Dollar Store has a set of all three for $7, but sometimes the 99-cent stores get the two smaller sizes at 99 cents each. Be sure to get the oval shaped without the indentation for handling, as that can touch the plate or film and scratch it.

For fiber prints, I just run an archival washer outside with the run-off going to the garden, bushes, or trees, and don't worry about it. It keeps the plants happy!

[Darin Boville]

And if I remember correctly Ilford came out with some water conservation guidelines that included something like intermittent water flow for print washing as "washing" was actually a leaching process and didn't require a constant flow of clean water.

I don't remember the source but I saw the same thing, way back when. Started washing print in trays, flipping through the prints every twenty minutes or so, water change every once in a while. Sometimes they sit overnight.

Seemed to work very well. All that running water is a waste since (I believe) the idea is diffusion.

--Darin

[Mark Sawyer]

Sometimes they sit overnight.


You don't want to do that to fiber based prints or film negatives. They'll waterlog and the gelatin will fall apart.

[ROL]

Looking down the road........Water here gets increasingly expensive and will only get worse. They get us to conserve and then hit us with a rate hike because revenues are down. It happens like clockwork.

I vaguely remember some water issue some years ago in England? And if I remember correctly Ilford came out with some water conservation guidelines that included something like intermittent water flow for print washing as "washing" was actually a leaching process and didn't require a constant flow of clean water.

Anyone remember this or have some insight.

Here in the West, "Whiskey's for drinkin', water's for fighten' over", as I'm sure you know.

Or your rate becomes set at some very low personal historical level because you conserve more than anyone else, and then pay exorbitant increases when you user as much as every one else averages.

The washing issues I recall had to do with some of their Kentmere line of papers in which the emulsion was disintegrating, floating in the wash water at 'normal' wash times, so they suggested shortening times by half. I guess that qualified as water conservation. Perhaps your confusing Ilford's film washing method (5 changes) with prints. It's hard to see logically without testing, just how hypo and such could be washed adequately from fiber without constant changes. But then that would be one more reason for ameliorating problem to start with by using s single fast fix, and a hypo eliminator – less to wash out.

[koh303]

But then that would be one more reason for ameliorating problem to start with by using s single fast fix, and a hypo eliminator – less to wash out.
+1

[Taija71A]

... And if I remember correctly Ilford came out with some water conservation guidelines that included something like intermittent water flow for print washing as "washing" was actually a leaching process and didn't require a constant flow of clean water.

Anyone remember this or have some insight?

_____

Is this perhaps... What you were referring to Kirk?
--

from the Ilford Web Site...

WHAT IS THE ILFORD PHOTO ARCHIVAL SEQUENCE?

"The ILFORD PHOTO Archival Sequence is a method of processing fiber base papers for maximum longevity... While reducing the amount of water and time used.

The method, which was fully tested more than a decade ago, requires the use of a non-hardening rapid fixer mixed at film strength.

After the paper has been developed and stopped, it is placed in such a fixer for 60 seconds with intermittent agitation.

Next the paper is placed in a running wash for five minutes, followed by an immersion in ILFORD PHOTO Wash Aid (1+4) for ten minutes with intermittent agitation.

The end of the sequence requires an additional five minute running wash."


http://theonlinephotographer.typepad.com/the_online_photographer/2011/07/fixer-doesnt-sink.html

--
Best regards,

-Tim.
_________

[Curt]

http://photo.net/columns/mjohnston/photography-assumptions/

A quick reference above that mentions an old David Vestal article on rinsing prints with successive water baths. Searched online and can't find the original article by Vestal but I remember it. Soaking in a few baths works well and uses less water than continuously running water.

Using a hypo clearing agent after the initial rinse before soaking helps.

I remember that article too, way back in time, that's probably why I do it. I can find the article but count me as having seen it.

I sent my Intellifaucet 750 back to Hass for refurbishing. This letting the water run through the old Kodak model is wasteful.

[Will Frostmill]

http://photo.net/columns/mjohnston/photography-assumptions/

A quick reference above that mentions an old David Vestal article on rinsing prints with successive water baths. Searched online and can't find the original article by Vestal but I remember it. Soaking in a few baths works well and uses less water than continuously running water.

Using a hypo clearing agent after the initial rinse before soaking helps.

I was just reading about this last month, when I picked up a copy of Vestal's Craft of Photography. (99¢ plus shipping on that online bookstore. )

[Kirk Gittings]

You don't want to do that to fiber based prints or film negatives. They'll waterlog and the gelatin will fall apart.

I have not found that with one overnight unless the ambient temperature is very warm and thus the holding tray water is very warm.

[Darin Boville]

You don't want to do that to fiber based prints or film negatives. They'll waterlog and the gelatin will fall apart.

Sometimes with work prints that I'd wash I'd leave them in too long--several days. Never had any problems with 24 hours. Three days was no good. The boundary must be somewhere in the middle...this was with Ilford Gallerie and Kodak Fine Art Elite, some time ago...

--Darin

[Michael Kadillak]

Sometimes with work prints that I'd wash I'd leave them in too long--several days. Never had any problems with 24 hours. Three days was no good. The boundary must be somewhere in the middle...this was with Ilford Gallerie and Kodak Fine Art Elite, some time ago...

--Darin

Ditto here. 24-48 hours in water film or Azo/lodima was perfectly fine.

[Darin Boville]

Sometimes with work prints that I'd wash I'd leave them in too long--several days. Never had any problems with 24 hours. Three days was no good. The boundary must be somewhere in the middle...this was with Ilford Gallerie and Kodak Fine Art Elite, some time ago...

--Darin

Just a footnote, I found that when leaving them in for long periods the center of the top print--especially with larger sheets--would sort of float to the surface and partially dry. I always left a test/work print on top (same print used in the stack to help me identify when I'd looped through each of the sheets one time.

--Darin

[Merg Ross]

I have not found that with one overnight unless the ambient temperature is very warm and thus the holding tray water is very warm.

This has worked for me for decades (prints, of course) without any adverse effect and a great saving of water. Twelve to eighteen hours soak at 75 degrees or less, wash aid followed by a short wash.

[cyrus]

The Ilford method, as far as I remember, basically consists of a series of water changes rather than having the water constantly-running. "Washing" prints happens through diffusion; time, temperature and the concentration differential are the primary factors that determine the diffusion rate. The water does not have to be constantly moving, as long as it is changed once enought time is allowed for the fixer to diffuse from the paper into the surrounding water, thus equalizing the concentration. A series of (warm) water changes should have the same effect as constantly running water, if not better since it takes a bit more time too, and you don't have to hope that your print washer is totally efficient in distributing the moving water over the entire print evenly. A fixer test should confirm this.

[Brian C. Miller]

I learned about the soak-and-dump from Bernhard Seuss' book. He recommended a few soak and dumps, with an overnight soak. One time, to his dismay, he watched the emulsion on a new paper slide right off into the tray.

I have also seen the soak-and-dump documented a few places on the web, with one recommending hypo clear, followed by three 30-min soaks, with changes inbetween.

[Kirk Gittings]

This has worked for me for decades (prints, of course) without any adverse effect and a great saving of water. Twelve to eighteen hours soak at 75 degrees or less, wash aid followed by a short wash.

Merg, how do you keep the water that warm overnight?

[Kirk Gittings]

_____

Is this perhaps... What you were referring to Kirk?
--

from the Ilford Web Site...

Yes I think that was it. Thanks.

WHAT IS THE ILFORD PHOTO ARCHIVAL SEQUENCE?

"The ILFORD PHOTO Archival Sequence is a method of processing fiber base papers for maximum longevity... While reducing the amount of water and time used.

The method, which was fully tested more than a decade ago, requires the use of a non-hardening rapid fixer mixed at film strength.

After the paper has been developed and stopped, it is placed in such a fixer for 60 seconds with intermittent agitation.

Next the paper is placed in a running wash for five minutes, followed by an immersion in ILFORD PHOTO Wash Aid (1+4) for ten minutes with intermittent agitation.

The end of the sequence requires an additional five minute running wash."


http://theonlinephotographer.typepad.com/the_online_photographer/2011/07/fixer-doesnt-sink.html

--
Best regards,

-Tim.
_________

[Merg Ross]

Merg, how do you keep the water that warm overnight?

Kirk, good question. My typical printing session starts early morning, so at the end of the session I have a six or eight hour head start on the soak process and control over the temperature. I dump periodically through the day and then continue soaking through the night. The night soak starts at 75 degrees and is rarely below 60 degrees by morning (my darkroom is small and well insulated). I have gone as long as 36 hour soaks without adverse effect, but only for convenience not necessity. Soaking is really the key to shortened wash times.

Your earlier post about less use of water and increased charges really hits home here as we enter a drought year. My darkroom wash water bypasses the city sewer and is saved for landscape use. I have become very water conscious in my old age!

[Curt]

I have not found that with one overnight unless the ambient temperature is very warm and thus the holding tray water is very warm.

This has been my experience. Way back in college I'd print late in the evening and leave them soaking after a few changes of water. The next afternoon after school I'd get them onto fiberglass screens. Never had a problem.

[Mark Sawyer]

I had trouble once leaving prints in overnight, (after that I didn't do it again! :rolleyes: ). The gelatin was so fragile I couldn't help but damage it.

[Struan Gray]

The best washing strategy is a common homework problem in physical chemistry. Because leaching proceeds with an exponential decay, for any given total amount of water and time, washing with two lots of half the water for half the time each removes more of the leachant than using all the water in one long soak.

Running water is what you get when you take this to its logical conclusion, but there is a gotcha. The leachant has to have time to diffuse into the clean water, and for thiosulphate complexes coming out of paper, the diffusion is so slow that you waste most of the water. In this case, a few cycles of fill, static soak and dump work just as well, and use far less water. Some people I've known even re-used the intermediate baths, making the second the new first, and so on. Residual silver testing is a little more difficult now that so many 'common' chemicals have disappeared from photo stores and local drugstores, but it can still be done to check that the wash is thorough enough.

The only gotcha with the fill-soak-dump method is that you should take care to avoid carry-over between baths. Fully empty the tray if you are going to dump and refill, or allow the surface water to run off the print as much as patience allows if moving prints between baths. Advanced physical chemistry students get to calculate how a relatively small amount of carry over can quite dramatically compromise the efficiency of the overall wash.

[BetterSense]

The best washing strategy is a common homework problem in physical chemistry. Because leaching proceeds with an exponential decay, for any given total amount of water and time, washing with two lots of half the water for half the time each removes more of the leachant than using all the water in one long soak.

Running water is what you get when you take this to its logical conclusion, but there is a gotcha. The leachant has to have time to diffuse into the clean water, and for thiosulphate complexes coming out of paper, the diffusion is so slow that you waste most of the water. In this case, a few cycles of fill, static soak and dump work just as well, and use far less water. Some people I've known even re-used the intermediate baths, making the second the new first, and so on. Residual silver testing is a little more difficult now that so many 'common' chemicals have disappeared from photo stores and local drugstores, but it can still be done to check that the wash is thorough enough.

The only gotcha with the fill-soak-dump method is that you should take care to avoid carry-over between baths. Fully empty the tray if you are going to dump and refill, or allow the surface water to run off the print as much as patience allows if moving prints between baths. Advanced physical chemistry students get to calculate how a relatively small amount of carry over can quite dramatically compromise the efficiency of the overall wash.

I will differ on several points. Note that most of my experience is with washing acids and bases off of semiconductor wafers in ultrapure water. This is typically monitored with a resistivity monitor.

Running water is not the "logical conclusion" you say it is, in fact it's the opposite. It is NOT better than repeated dumps, unless perhaps you have perfect laminar flow in your tank, so that incoming water does not mix with existing water in the tank. It should be intuitively obvious that this never happens, as the incoming water always mixes together with water in the tank, even in million-dollar computer-designed wash tanks. This means that running water is actually the worst of both worlds...extreme amounts of "carry over", with extreme amounts of water usage. You can test this yourself with a resistivity meter* and this has been done many times in the semiconductor industry. Repeated dumps are not "almost as good as" running water, they are "better than" running water. Overflow rinsing is still used DESPITE it's inferiority, because depending on the surface state of the wafers and relative cleanliness of the water vs. the air, exposing the wafers to air can be a Bad Thing. But it's never done because it's better at rinsing. Dumping is better. Actually, best of all from a washing perspective is initial washdown spray rinsing, followed by dump rinsing, but spray rinsing is even worse than dump rinsing for contamination from airborn particles (particles too small to be visible, even with an optical microscope).

Carryover isn't as huge of a deal as you make it sound. It makes a big difference compared to no carry over whatsoever, but it takes extreme amounts of carryover to make dump rinsing as bad as overflow rinsing.

I'm not going to attack the issue of how long prints need to be in clean water for all the hypo to diffuse out of the emulsion/print. People like to talk about this a lot but I have never once seen a figure for the diffusion coefficient of hypo in gelatin or cotton. Actual data would be neat.

*To test it for print washing, try this: put 1 teaspoon of food coloring in your print washer and mix well. Turn on the water. Write down how long it takes for the food coloring to disappear. Unless you have a perfect laminar flow washer, it will be a while, because the food coloring will mix with the incoming clean water. Next, repeat the test with dump rinsing. Put 1 teaspoon of food coloring in your print washer, mix it up, and dump it all out, and fill it back up. Repeat. Or rather, don't bother to repeat, because you probably won't see any food coloring...you dumped it all out.

[Struan Gray]

I've washed wafers too. Well enough to see the one, single impurity atom in a square micron with my UHV STM. My respectful opinion is that the perfectionism I developed for that wasn't much use when it came to washing fixing complexes out of photographic paper. The timescales and processes by which the contaminants are removed are too different.

Everyone is free to develop their own wash routines. Residual silver tests are not hard.

[Larry Gebhardt]

I rinse with running water for about a minute in a tray, then transfer to the archival washer. When I'm cleaning up for the night I run the washer at a medium flow to change out the water (about 10 to 15 minutes) and then let it sit over night. In the morning I remove the prints. The residual fixer tests show this works well (at least in my darkroom).

I missed a print in the washer one day, and left the washer full since I thought I would be back to it that evening. When I came back a few days later the emulsion had slid off the paper and made a huge sticky mess in the washer. But I haven't had an issue with leaving them over night.

[Jim Jones]

. . . Some people I've known even re-used the intermediate baths, making the second the new first, and so on. . . .

I've done this for decades. When producing many 8x10 RC prints in a hurry, washing about 30 prints in three 5" deep trays with agitation worked well. This used a very few ounces of water per print. Leftover prints from 40 years ago are still good.

[ROL]

WHAT IS THE ILFORD PHOTO ARCHIVAL SEQUENCE?

"The ILFORD PHOTO Archival Sequence is a method of processing fiber base papers for maximum longevity[COLOR="#696969"]... While reducing the amount of water and time used.

The method, which was fully tested more than a decade ago, requires the use of a non-hardening rapid fixer mixed at film strength.

After the paper has been developed and stopped, it is placed in such a fixer for 60 seconds with intermittent agitation.

Next the paper is placed in a running wash for five minutes, followed by an immersion in ILFORD PHOTO Wash Aid (1+4) for ten minutes with intermittent agitation.

The end of the sequence requires an additional five minute running wash."

Yeah, I remember coming across this occasionally in the past. I always thought of it as some kind of advertising scheme for the Ilford wash aid, even though I know that just can't be true, because of the unreferenced testing for what amounts to 25% of the time for 'normal' constant flow washing.


To summarize thus far? (correct me if I'm wrong):


rapid fix
wash aid/hypo eliminator
constant flow, as opposed to fill and dump
reduce normal time as much as you dare!
results depend on paper type*


As regards the prevention of leaching the whites from a paper, I still see no real conclusion here (though that seems to be Ilford's contention – perhaps(?) only having to do with their papers), and have experienced no perceptible differences myself.

FWIW, my mural prints are washed in a homemade 'flat washer' since they cannot be washed in my largest commercial washers (and I'm not rich). Even though they receive constant water flow, I manually dump the water many times throughout the wash, and shuffle prints, which can 'stick' together, the topmost otherwise becoming 'dry' during the wash. I wash as long as 1½ hours or more on occasion to have any reasonable expectation of a normal wash. Never a problem with results (my back, yes), so far.


http://www.rangeoflightphotography.com/SupportPics/DarkroomPix/DR5.jpg



* I've had Kentmere Fineprint emulsion dissolve in the developer, and no problem with Oriental swimming overnight.

[Doremus Scudder]

...

To summarize thus far? (correct me if I'm wrong):


rapid fix
wash aid/hypo eliminator
constant flow, as opposed to fill and dump
reduce normal time as much as you dare!
results depend on paper type*


As regards the prevention of leaching the whites from a paper, I still see no real conclusion here (though that seems to be Ilford's contention – perhaps(?) only having to do with their papers), and have experienced no perceptible differences myself. ...

Hi Ben,

Just to prevent confusion: Hypo Clear aka Kodak Hypo Clearing Agent is basically the same as Ilford Wash Aid and other sodium-sulfite-based wash aids. Hypo Eliminator was a Kodak product/formula based on hydrogen peroxide and its use is no longer recommended!

As for this whole discussion on washing, everyone should take a look at Les McClean's article "Mysteries of the Vortex" available here
http://www.film-and-darkroom-user.org.uk/forum/showthread.php?t=296
as well as the discussion of washing in Ctien's "Post Exposure," which is available for pdf download for free somewhere on the Internet.

The whole question of optimizing water use for print washing, I think, misses an important point. Yes, we can, through testing and trying different schemes, come up with a washing method that uses the least amount of water for the least amount of time. However, by optimizing these variables, we are eliminating any kind of safety margin we might have and risk under-washing the prints unless stringent quality control is used.

I prefer to err on the side of "guaranteed adequate wash" and use a bit more water plus a bit more time than my residual hypo test tells me is necessary for a good wash.

FWIW, I find it only logical what BetterSense maintains above, that a constant running water wash without dumping is actually less efficient. Plus, since leaching is the principal mechanism for washing after the intial carried-over fixer is rinsed off, I see no reason for massive water flow.

I use a combination of minimum water flow and fill-and-dump. My washers have been modified (actually just added a sprayer set-up made from perforated tubing) to spray water onto the water surface in the washer, which then drains from the bottom of the washer. The flow is very low. Then, at roughly 20-minute intervals, I drain the washer tank and refill it. This is my largest use of water, since the tanks do hold a bit. At the end of an hour, I have emptied and refilled the tank twice, and there has been a slow water flow for the rest of the time. I then pull a print and test it for residual hypo. If it's fine, I put it back in and let it sit for at least another 20-30 minutes with the minimum flow (part of this is to leach out the brighteners - more later).

I realize water is a precious resource and am as conservative as I can be using water. On the other hand, I'm not about to cut corners on print washing any more than I would on fixer freshness, etc.

As to optical brighteners: I thought I had a chart somewhere showing the leaching of optical brighteners in paper over time, but couldn't find it. At any rate, IIRC, the bulk of the brighteners, ca. 70+%, are removed after about an hour in the wash anyway; after two hours there is practically nothing left in the print in the way of brighteners. For prints that are displayed, the rest of the brighteners bleach out after a period of exposure to light, from what I understand, although the by-products are left in the emulsion.

I, for one, dislike brighteners for a couple of reasons. First, I think they make the whites look fake. I like the look of the paper base and the baryta coating just the way it is; I don't need it to fluoresce. I have always liked the look of the whites in the prints that have been in the washer longer than the work prints I use that have really just been given a cursory wash. And, I always liked the whites better under incandescent lighting (no UV = no fluorescence of brighteners) than in sunlight...

Second, have you ever seen a white shirt that has been sitting in the closet, washed but unworn, for a few months? It turns yellow because the brighteners degrade. If they use those kind of optical brighteners in paper, I don't want any, thanks. I know Bruce Barnbaum and Les McLean both advocate leaching out the brighteners. Many papers are made without them. Any paper made before about 1953 didn't have them; I don't see a lot of people complaining about the whites in Weston and Adams and Cunningham et al. prints from before then ;)

Best,

Doremus

[W K Longcor]

I begin by admitting that I have been out of the darkroom for almost two decades now. So take anything I say with a grain of salt. Back in the 1970's, I began having problems with the emulsion softening and lifting off the paper base. My Kodak tech rep. stopped by one day and told me that the chemical make-up of the water could make such a problem. Particularly very "soft" water. Turns out, the building did have a water softener. (Eventually, we installed by-pass plumbing around the softener to our print wash area). He suggested tossing a "hand full" of epsom salts into the wash water. I still have prints from back then. The epsom salts did no harm and did keep the emulsion on the paper while wet. So, if you want to try overnight soaks -- maybe try some epsom salts-----worthy of a try???

[cyrus]

I've never had a problem with gelatin sloughing off a print or a negative, and I've left the stuff in water sometimes for many days. I don't know why

[Kirk Gittings]

I don't know why either, maybe hardness is a plus or minus or paper design? Our water here is somewhat hard and at two days it definitely becomes a problem.

[NancyP]

Here's a variation on Ken Lee's dish-rack:
30-CD acrylic rack. 4 x 5 fits beautifully. I even found a cheap box fitting the rack perfectly.
http://www.containerstore.com/shop/collections/mediaStorage/cDsCassettes?productId=10010451

[natelfo]

I installed a reverse osmosis system in my darkroom due to hard water issues. I can process 6 sheets of 4x5, 2 rolls of 120, or 3 rolls of 35mm using a little over 2 gallons of water. I keep several 2 gallon containers full of RO filtered water because the RO tank itself loses pressure after only a few minutes, so I use the tanks for the actual processing, and I only use RO water throughout the entire process. Here's my washing process:
After fixing, fill the dev tank with water, slosh around constantly for about 2 minutes. Dump, then refill. Let sit for about 5 minutes, sloshing around a few times each minute. Dump, refill, let sit for 5 minutes. Dump, fill with Heico Permawash (or any other hypo clearing agent), slosh around for about 2 minutes. Dump, then repeat the same 3 rinse cycles as before, but I let the last one sit for about 10 minutes. One last quick rinse, then photo flow. Never had an issue with film not being washed enough.
As an added bonus, keeping several tanks of water helps ensure that the water I use is always the same temperature, which is within 2 degrees F of my house thermostat.

[Peter De Smidt]

A small amount of residual fixer in the paper provides some protection from image deterioration due to pollutants, but so does some types of toning. So, if you want increased protection, you can either wash the paper until the proper level of fixer is left in the paper, or you can tone the print in selenium/sulphide and use hypo eliminator (Hydrogen peroxide + ammonia), along with a short wash. The book Way Beyond Monochrome should have a good summary of current thinking on these topics.

[Mark MacKenzie]

Just wanted to say I have learned a lot of good ideas from this thread. Thank you, all.

[ROL]

Just wanted to say I have learned a lot of good ideas from this thread. Thank you, all.

:).

[Kirk Gittings]

ditto

[tgtaylor]

"...consists of a series of water changes rather than having the water constantly-running..."

What Cyrus says is correct: It's how many times you change the water that really count. If you're truly interested in conserving water I would suggest that you start with an alkaline fixer such as TF-4, TF-5, etc, that requires minimal washing to start with. Leaving your print in the water for hours or even days as suggested in some of the above posts is harmful to the paper and the image - especially RC - and the mfg data sheets usually cautions you against extended washing.

With regard to film, here is a method from California that was in vogue during past water shortages:

1. Fill the tank and dump.
2. Fill the tank, agitate 5 times, and dump.
3. Fill the tank, agitate 10 times, and dump.
4. Fill the tank, agitate 20 times, and dump.
5. Fill the tank, agitate 40 times, and dump.

The above gives you 5 changes of water in, presumably 5 minutes, which is less than the 10 changes of water recommended by Jobo but probably sufficient if using an alkaline fixer.

Thomas

[Domingo A. Siliceo]

My method for washing copies is to plunge them in water in a normal tray and use a submersible fish tank water pump to constantly move that water. Then I do four water changes, increasing the time the copy rests in the tray with every change — while the last change, the copy remains some hours inside the water.

[j.e.simmons]

Ron Mowery had some posts on this on APUG years ago. As I remember, he said fixer diffuses into the wash water at a certain rate, and that when the percentage of fixer in the paper and in the water balanced, diffusion stopped. Thus, dump the water and add new water. He said that it took about five minutes to reach that state, and that agitation didn't change anything. Ilford says to agitate.

My process is to use five separate washes, agitate in each per Ilford's suggestion and leave standing in each per Kodak's suggestion.

[Jmarmck]

As an aside, the pricing of water you describe is a conservation measure employed by many municipalities. It is called conservation pricing. The desired effect is exactly as you describe, Kirk. Is seems to be working. Problem is when the reservoirs refill the prices rarely go back down.

The bottom line is that as water becomes a more rare commodity the more conservation pricing will be implemented. The washing method will change.


How does your yard look?

[Ian Gordon Bilson]

Post #41 looks remarkably like the Ilford Wash Method,with a few iterations added,but that was for film.
I prefer to think it works,and well, especially if the wait period is used. And the emulsion science that states that a slightly less than perfect removal of thiosulphates is a positive outcome has me puzzled.
Perhaps it is not "perfect science" after all.

[Kirk Gittings]

As an aside, the pricing of water you describe is a conservation measure employed by many municipalities. It is called conservation pricing. The desired effect is exactly as you describe, Kirk. Is seems to be working. Problem is when the reservoirs refill the prices rarely go back down.

The bottom line is that as water becomes a more rare commodity the more conservation pricing will be implemented. The washing method will change.


How does your yard look?

Our yard has been nearly completely xeric for about 18 years.