The white stains that accumulate on the inside of a flower vase are hard water deposits, and white vinegar dissolves these deposits. You may want to scrub, though, and that may be difficult if the vase has a narrow neck. Use rice for a scrubber so that you don’t have to try to stick your hand in the vase.
Eliminate Stains with White Vinegar
The easiest way to clean hard water deposits on the inside of the glass vase is to fill it with vinegar ; let the vinegar sit for many hours and then pour it away. If some stains stay, wipe them off with a nonabrasive cloth before the vinegar has dried. Vinegar contains acetic acidthat has a low enough pH to dissolve the salts that cause the white stains.
Scrub with Rice
If your vase has a narrow neck and the stains aren’t coming out, you may be able to acquire a bottle washer in it to scrub them. If it doesn’t achieve all the contours of this vase, or the vase is quite fragile, pour into a few rice while the vase is still full of vinegar; then cover the top and shake. The rice acts as a gentle scrubber to remove the stains.