Cleaning hard water bathtub stains?

Try making a paste with baking soda and white vinegar.

I sprinkled baking soda on mine and then sprayed down with vinegar and that worked well. I saw on here someone had recommended a product called Barkeepers Friend. It is sold as a powder like Comet and you can get it at Home Depot and other places. I am going to buy some this week, it gets rave reviews for dealing with hard water stains.

Baking soda & vinegar with a little elbow grease. IF your tub is an old cast iron one...Bonami Powder does wonders for the stains that the Baking Soda & vinegar doesn't get out.

Try Lime Away Toilet Bowl Cleaner. I have been using this for cleaning my shower door and tile. It is easy and cheap; you can buy this at the dollar store. I squeeze a liberal amount on the area to cover and spread it over the area. I let it set for about 10 minutes. Then I take a scouring sponge and scrub a little bit and rinse.