How to clean hard water stains? (Copenhagen)

Hi all,

Can anyone suggest a good, safe-ish product to use (and how to use) to remove hard water stains from 1. Kitchen counter (laminate top) 2. From the bathroom tile and sink

I would like to hear what has worked best for everyone.
I heard its a huge cleaning fee if I turn over the apartment at the end of the lease with hard water stains. So I would like to get it under control ASAP! :)

Thanks!!