I have extremely hard water and had lime deposits that would not come off no matter what I tried. I found "The Works" at Dollar Tree, it works wonders, no excess scrubbing.
I had purchased some toilet bowl cleaner at the Dollar Tree. I had some hard water and rust stains in my toilet, the immediately disappeared! Since it did so well I decided to try it on my old cast iron tub that had spots. It cleaned it, too.
For hard water stains in the toilet, I use a piece of pumice and really scrub. It has always worked without scratching. Give it a try.
Add your voice to the conversation. Click here to answer this question.