What is the best way to clean hard water stains off shower, and sink?

I find vinegar works well

Magic eraser by Mr. Clean. Make sure you wet it first. Also, Barkeepers Friend works well. You can find it at Dollar General. Make a paste with it and let it sit then scrub with a damp cloth or the magic eraser.

Try a dryer sheet too.

Make a mixture of white vinegar and water 50/50 a dab of dish soap and a dab of jet dry.

Have you tired using a pumice stone? It has worked for me!

Vinegar!

Soak cloths with white vinegar and lay over stained areas. Leave overnight. Clean normally and rinse. For shower head, fill Ziploc bag with enough vinegar to cover head. Hold bag on with rubber band. Leave overnight. Then clean normally and rinse.

CLR cleaner works wonders without scrubbing.

My shower area is huge. Like could fit 4 people big. But my water leaves such bad rust water stains. Almost to the point I almost give up. Any advise?

Fill a spray bottle with a 50/50 solution of Dawn dish soap and vinegar. Spray it on the hard water stains and let it work. If they are tougher stains, you may have to scrub with a plastic scrubber.

I use a mixture in a 32 ox water bottle of 5-6 oz blue dawn and fill with white vinegar, shake it up and squirt onto the water spots. Clean with a microfiber cloth, rinse and dry.