I noticed that mineral water with high mineralization doesn't have salt flakes floating on the bottom of the bottle on store shelves, but when I open one, after some time they start accumulating. Does it have something to do with decarbonation?
2 Answers
http://en.wikipedia.org/wiki/Solubility
Salt solubility decreases with decreasing pressure.
It could be gases (oxygen or carbon dioxide) from the air, competing as solvents with the salts. I know the reverse effect: adding salt tends to drive out gases.
I'm not sure whether this gas explanation is more significant than the pressure explanation. But, you could do an experiment: briefly let the pressure out and then retighten the cap without letting fresh air enter, and see if the crystals still form.