I am setting up my 2 (actually 3 as I will be setting up Magnesium as well) part doser and I was just wondering if it's safe to use old vinegar jugs as the jugs for my Ak, Calc. and Mg supplements? These jugs had some Heinz distilled white vinegar in them but are perfect at 1 gal. each, I have since rinsed them with hot water and soaked them in hot water over night...do you think they are safe to put the supplements in now?