calcium deposits on glass?

[Swingline77]

I have a tank with a rim. When I was using it for freshwater, I was filling it to above the bottom of the rim. This way, calcium deposits from the tap water would deposit in an area not visible when looking at the tank. With saltwater, can these calcium deposits be totally removed with vinegar, etc.? Will the glass be etched in any way? thanks.

 

[Ludders]

I use a razor blade to get rid of anything like this along the water line. Probably do it once every 3 months.