How to remove hard water stain in toilet?

We have the same problem here. I use a money to get rid of the ring and I have heard putting WD40 around the inside delays the return, because it always comes back.

I live in AZ too hardest water in the world!!!!! remove some of the water to below the line place an old wash cloth soaked in straight vinegar or CLR on top of the ring and let it soak at least 10 minutes or until it's dissolved scrub it with stiff toilet bowl brush or green scrubber sponge; adding some 1-2 cups white vinegar in back of tank every month and the bowl and let it sit over night will help too. when the mineral build up forms it turns dark from urine or feces getting stuck on it. yeah even if you think it's clean need to disinfect with bleach

Hi, Karen!

A pumice stone (like one used on the feet) works to remove rings in the toilet! They are very inexpensive and can be found at dollar or discount stores. I hope this helps!

Try Coca Cola and if that doesn’t work. Try the Denture Tablets from Dollar store. With tablets make sure you empty out the water that’s in there. Put hot water in there then the tablets. Put a couple in there.

Here's a great article on removing hard water stains from a toilet.