It seams to me that there might be some confusion as to one-shot and re-use from what I can tell. To me one-shot is use it and down the drain. Re-use is do a session and pour it in a bottle for another day. I never pour mixed fixer in a bottle. I mix a batch and use it for that session watching my print or film quantities. Using the recommended numbers given by Ilford for their Rapid Fix. I normally wait until I have 10 or 15 rolls to develope before I start mixing new batches.
It would take some very unusual combination of chemical
Originally Posted by Stoo Batchelor
interaction to precipitate elemental silver within the fixer
solution. Off hand I can't think of any combination of
chemistries we involved with darkroom chemistry
might concoct on purpose which would cause
such a chemical reaction.
I've read many APUG posts dealing with fixer but yours is
a first ever seen warning of fixers "full of silver particles"
In years past I've put a lot of film through the same lot
of fixer with no problems. I dare say 9 out of 10 or more
APUG'ers reuse fixer. Film strips, Ag indicator paper, silver
load drops, and by count, are the methods used to
For myself I use fixer fresh each roll or print, very
dilute one-shot. Dan
For film, I use a neutral pH rapid fixer that I mix fresh for each use. I use it once and dump it.
Originally Posted by 23mjm
For fixing paper I use two fixing baths - both made fresh at the start of the printing session. I dump them at the end of the printing session.
Originally Posted by dancqu
Please take a look at the link below;
Now, as I have said, I am no expert on film development, or in anything else when it comes to photography for that matter. I speak as I find. In number 1, in the article, it quotes...."Silver attaches readily to surfaces"..
Now, as this is an article on silver recovery from darkroom fixers, and it also warns of the dangers of discharging used fixer in to the enviroment, I can only assume that there is a silver content in used fixer. At what point a fixer reaches a point where as it becomes a hazard does not concern me. The fact is that used fixer will have silver particles, or what ever word you wish to use, in it. As this silver is capable of attaching itself to surfaces, in this instance it would be the soft emulsion of my film, I have chosen that during my own development routine I do not wish to subject my film to such a risk, however small.
Yes, as this post proves there are many APUGers re-using fixer with no complaint, and they are very happy with their results, as I am with mine. So there is no reason for any of us to change our development routines.
EDIT...I thought I would just add PARTICLE/A MINUTE PORTION OF MATTER. and please, I am in no way trying to sound smart here (I always find that quite difficult!)
Also worth stressing that if you do put your fixer down the sink, the more 'used' it is the worse it definitely is for the environment. Another reason, apart from archival reasons, I don't use it to exhaustion. Although one of my NY res's might be to dispose of all my chems (apart from developer) via the Council hazardous waste route...
Originally Posted by Stoo Batchelor
I'm going to fight with your logic. :) I am of the opinion that 1 unit of fixer with .1 units of silver in it is better for the environment than 100 units of fixer with .1 units of silver. The total silver exposure to the environment is the same (you are shooting the same amount of film or processing the same number of prints whether you reuse your fixer or not), but you are discarding more fixer which is itself a pollutant.
Originally Posted by catem
Certainly fixer with strong amounts of silver in it will be bad for the environment, but diluting the silver with fixer isn't exactly helping. You're just discarding more pollutants.
I'm no expert on any of this. Both Ilford and Kodak give similar exhaustion rates for their fixers and these are undoubtedly conservative figures due to many unknown factors once the product is in the hands of the consumer. Other brands probably have similar exhaustion rates but I would consider dumping them a little more often than either Ilford or Kodak unless there are manufacturer's recommendations available that state otherwise.
Personally, I use film strength, non-hardening rapid fixer as a two-bath solution for prints. With the initial chemicals, I dump the first bath a little more often than is recommended and move the second bath up to number one. This rotation keeps the second bath fresh and the first bath used to near exhaustion. With film fixer, I test the chemical with a film leader or dump the fixer after six months or so. The amount of film I shoot and process can vary considerably over time. Sometimes I shoot dozens of rolls in a month and sometimes I shoot nothing for several months.
As for the one-shot fixer idea, I make no sense of the notion for dumping out perfectly good chemicals, especially when based on an environmental/conservationist argument. It's wasteful and it simply means the consumption of more chemicals and more chemicals being dumped into the environment in the long run.
I use naaco fixer test or whatever it's called. One drop into a bit of fixer will tell you if it's good to go. I had developed about 40 sheets of 4x5 tri-x no problem but went to develop a roll of 120 tmax and it didn't clear.
I don't dump 'perfectly good chemicals' - only chemicals I can no longer rely on to do the job I want :)
Originally Posted by Lee Shively
I don't want to overplay the environmental issue overmuch as most sewer systems are able to cope with the amounts of silver dumped from home darkrooms- when you think of household chemicals some of those are worse. HOWEVER with fixer it is the sludge that forms that though unlikely to cause harm may potentially cause a degree of harm in larger quantities. As I understand it, this is lessened if you release less exhausted fixer in greater dilution (achievable by using more running water as you dispose). It may be small difference in the larger scheme of things but on the other hand every little helps and it makes me feel better.
I use Edwal Hypo check at the start and at the finish of large batch processing such as 4x5 in tanks. With Edwal I can tell when the fix is about finished, the check with start to cloud up then clear after a second or two, thats when I dump and fix fresh.
Originally Posted by Phillip P. Dimor