It is fine. Lots of people dilute it one to one so you could consider that every liter you start with from your mix needs to have 2/3ds liter water added to make it one to one. Or if you tend to use only one or two types of film then just run a test and push your normal time a little bit to see where it needs to be and then just use it like that.
Dennis
PS that 2/3ds liter water is quick math in my head which is fallible. I figured that all 6 liters you have mixed need an equal part of 4 more liters water to make it 1-1.
Uhm, turned out that I was wrong, and stupid. Long story short, I had to clean up (I do my mixing at the kitchen table) and after putting everything in bottles I had 5L after all. (Strange, because I weighed it (on a scale going to 5kg) after removing +- 1L it still weighed about 5kg...)
I was thinking of removing this post, but since I had troubles finding something about this, I'm going to let it be. Carry my stupidity into the future!!!
It would have been fine except of course you lose the option to process in stock (1+0) solution. If you want to reach the usual 1+1 dilution (10L from a packet) you would of course dilute 6+4.
I actually do the opposite and mix my XTOL into 4L (1.25x concentrated). Then when processing, I dilute 2+3 to get the normal dilution.
Good to know your dilemma turned out to be nothing at all! I wonder how many responses this will garner given that the "problem" was resolved in the 3rd post?
The only real problem I can think of would be shorter shelf life. Since it is not quite as concentrated as the stock solution is supposed to be for storage it will be less stable. How much less stable, I don't know.
Michael makes useful point. Sooner or later someone out of the many thousands of us will actually mix 6L as stock by mistake. As stock is nearly 5L of water anyway then at what point does the extra water reduce the life of the "stock" if at all?
Provided that the "stock" is dumped after every use then why can't the 6L be made into 10L of "1+1 stock" and remain safe to use for as long as stock solution lasts?