In a sealed bottle, mixed colour dev will last for up to a week according to the Kodak instructions supplied. I've certainly used week-old solution without any problems. (Granted, if I've got solution that old I only use it on test rolls or unimportant stuff, but even so I've never noticed a problem. Of course I'm not one of those people who whips a sensitometer out to decide if their shots are any good
.)
Dear Tim,
The remark I made about the poor keeping qualities of the colour developer is based on the bad experience I had when I was a novice in E-6 processing.
I used to mix up the whole 5 lit. and use, at first, the half of it as the machine I am working with, only can take max. 2,7 lit. of working fluid and 2,5 lit. are quite enough for one run.
I kept the second half in a container, in the dark and on working temperature, for the time as needed for the loading, the warming up of the fluids (and eventually, in the winter, the films to), the processing, the unloading and the rinsing of the machine, say about 2 hours.
Then, when I used the other half for the second run, the results were so bad, compared to the first run, that I stopped doing this (this is where the use of a densitometer and test strips are interesting : self discipline, process control, the answer on some doubts and consistency).
Right now I mix up the half of the concentrate as needed for each run, I do not mind the little extra work it takes.
And, BTW, the use of Dust-Off seems effective to me...
This is, of course, my experience and opinion, yours is as valuable as mine is!
Good luck,
Philippe