Apple cider vinegar/galvanized water container-help

[Bonnie in western WA]

The white powder you're seeing built up on the galvanized water can is actually "white rust", which is what happens to galvanized metal that gets wet. (I work with galvanized metal daily, and we can't store it outside in the elements)

I have a plastic, 3 gallon water can. Does anyone know how much ACV to add to it to keep the slime build up out of the tray?

1 tablespoon ACV per 1 gallon water is what I've already read.