As a corollary question: if you mix a 1 liter working solution, but only use, say, 300 ML because you are just doing 1 roll of 35mm in a Paterson tank, do you pour the 300 ML used solution back into the 1 liter working solution jug? Sometimes I use a little, sometimes I use a lot, depending on what I'm developing (a mix of 35mm, 120, and 4x5 which have different volume demands).
I suppose I could store the used working solution (dev and blix) in a separate jug, but I have not done this before. I just keep track of how much the total liter has processed, and pour the used solution back into the working solution container.
I suppose alternatively I could always use the maximum amount of working solution, even if I just have one roll of 35mm to process.