Claire Senft said:
Since water usage is so critical to you, I would reccommend Hypo Eliminator. It is much more effective than washing aids. It uses equal parts of hydrogen peroxide and household ammonia. Some feel that it will weaken the fibers on fiber based paper. My experience has shown that some papers show frilling of the emulsion but most do not.
The following are excerpts from the thread (URL below), posted by Richard Knoppow. These excerpts are consistent with my own darkroom experience.
http://www.photokb.com/Uwe/Forum.aspx/photo-darkroom/765/Hypo-Eliminator-Toner-Archival
HE-1 can be made from household ammonia and drugstore
peroxide, both are about the right strength. The Ammonia
should be just ammonia, not the kind with detergent in it.
In order to be fully effective some potassium bromide
should be added. For those interested the formula is:
Kodak HE-1 Hypo Eliminator
Water 500.0 ml
Hydrogen Peroxide (3%) 125.0 ml
Ammonia Solution 100.0 ml
Potassium Bromide 15.0 grams
Water to make 1.0 liter
The Ammonia solution called for is Ammonia, 28% diluted 1
part to 9 parts water, i.e. 2.8%. Household Ammonia is
generally about 3%.
If the bromide is not added the eliminator will not remove
some hypo-silver complexes.
Note that Hypo Eliminator is alkaline enough to cause
disruptions in the gelatin of some materials (pin holes).
This is generally insignificant for prints but is not for
film. Hypo Eliminator should NEVER be used for film.
Further, since the main effect of the eliminator is to
remove hypo from paper support it is really unnecessary for
film or RC prints.
Kodak recommends its use only when one has problems with
toning.
Images that are completely free of hypo may be unusually
vulnerable to oxidative agents in the air. These are very
common and include auto exhaust, exhaust from gas heaters or
stoves, paint fumes, and many other sources. While in the
past it was thought vital for long print life to remove
absolutely all hypo it turns out that it isn't necessary
and can be counterproductive.
The point is that it (i.e. Hypo Eliminator) is not really necessary. For film or fiber paper sufficient washing for archival life can be gotten by using a wash aid (i.e., HCA) followed by a reasonably short wash. Prints are more likely to last if toned especially if they are to be displayed. Negatives generally
don't need toning.
RC paper does not need wash aid because it washes out very quickly
even when fixed in hardening fixer.
The two-bath fixer IS necessary unless you don't need (fiber based) prints to
last for more than a few years.
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com