Hi all, I`ve already found one of my favourite bottles (I love that ones, wide rim, good cap, high quality white material) with very old mixed D76... as you can imagine, it is completely stained inside. I have two questions: 1. There was a solution to remove this developer staining from containers. I believe I used to use something made by Tetenal... I cannot remember it. I don`t have any formulary here; does anybody knows what could I use? 2. I also try to remember that fresh D76 becomes more active if mixed or contaminated with older D76 solution... have you experienced if that staining inside the containers will corrupt fresh D76? I believe it doesn`t, but to be sincere I`m not sure at all. Thank you.