I switched over to XTOL Replenised over a year ago after my 1 1/2 year old died suddenly. As I mostly use reversals, it can take a while to use it all up. I have been pleased with the results. But after a year of using this batch, 1 still have 1 ltr of unused xtol that could actually be dead without me knowing. My question is, does it matter? I am unsure how the replenised/stock react to each other under that situation. Would there be enough life in the replenish bottle (2l) to compensate? I am asking that question beceause I would like to know, not because I am too cheep to mix up anouther pack.