Originally Posted By: SwampDonkey
I often leave water bottles in my truck and they freeze overnight, after I thaw them out there is what looks like a small amount of white sediment in the bottom; does anyone know what this stuff is?

Mike


I suspect that that that white powder is just normal minerals. Mostly calcium and magnesium. Most non-distilled water has a small amount of these minerals in it and they tend to precipitate out as the water freezes. In reasonable amounts both magnesium and calcium are necessary minerals for human health. Most Americans are not getting enough.