The powdered fix may well be all sodium thiosulfate, in which case, you can mix small batches at will. But fix keeps much better than developers, the stock solution should last 1 - 2 years.
FWIW, I and many others have found that the "concertina" bottles tend to leak air, glass or PETE plastic are better.
Recycled wine "boxes" are great for storage too.
Thanks for all the input guys, appreciate it. I've not been so worried about the cost of wasting chem, since as you say, it's cheap, and particularly fixer. It's more just that I'm tight (good Scottish upbringing!) and don't like to waste anything.
I had wondered about the concertina bottles leaking, at the moment I only use them for my dilute Selenium and working solutions of fixer and paper dev, which might last a few sessions. And a small one for fixer concentrate too. My stock developers both live in large bladders, and store really well.. Maybe I'll have to get another one to pop fixer in and just start getting the 5L bottles.
Thanks again for the comments.
I'm not sure if you realize fixers are re-usable until exhausted. They don't really deteriorate by exposure to oxygen like developers and HCA would. I use mine until specified number of films/papers are processed or 6 months. Unless you are doing HUGE volume, it will certainly last longer than few printing sessions.
Also, selenium working solution lasts and lasts. I think I used my 1:40 solution for a year. At which point, the ammonia smell was weak and action was equally weak, so I replaced it.
This type of bottle is the worst possible choice for two reasons. The soft polyethylene that they are made of is very permeable to oxygen and not good for developers. Because of their design they are impossible to clean should anything get on the inner surface. Soft drink bottles made of PET plastic are a good choice and are virtually free.
Originally Posted by SteveR
I've got a 5L bottle of Agfa fixer that's been open for over 2 years so far, and probably still about a litre left. I didn't bother decanting the concentrate into smaller bottles or using Protectan. I'd guess the date of manufacture to be at least 5 years ago, because I bought the bottle for 17p when Jessops were having a clearout!
Still works the same as when first opened, and yes I do test the occasional print with selenium toner, and film clearing time just to be sure.
Thanks again for that input guys. Yes, my working fixer hangs around for a few sessions or more, I usually end up just splashing a little extra stock in I feel it's getting a bit tired, then replace it after that session. I had a great collection of these concertina bottles a number of years ago, in the darkroom I learnt in nearly 20 years ago they were all we had, but then I found out about their shortcomings! That's why now I only use them for working solutions that are only going to be in them for a couple weeks, and my dilute selenium, figuring it should last well no matter where I put it. My current batch has been in a concertina bottle and going strong for over two years, with jut a little top-up when times get too far over the 3 minute mark.
Good to hear of stock fixers lasting a while, I had always assumed (I think the Ilford data may state?) that 6 months was the limit for opened bottles, and one week the limit for working solution... Or maybe I have just always err'd on the cautious side.